Cages For Collection Research Articles

373 Effect of Cu and Zn contents in growing finishing pig diets on animal performance and Cu and Zn content in manure, according to three manure management chains

Abstract Copper (Cu) and zinc (Zn) are essential nutrients for swine. However, as pigs have a low retention rate for these elements, more than 90% of ingested Cu and Zn are excreted, mainly in feces. After spreading manure, these trace elements could accumulate in the soil and potentially have negative environmental effects. Moreover, Cu and Zn are also limited natural resources that should be preserved. A better understanding of the behavior of these elements throughout the feed-animal-effluent-treatment continuum according to feed composition and manure management chain is thus required to propose alternative ways to reduce these environmental impacts. Three feeding strategies differing in their Cu and Zn contents were compared in 72 growing-finishing pigs raised in individual pens [from 24.3 ± 3.3 up to 110 ± 9.0 kg body weight (BW), one-half males; and one-half females] a first diet with Cu and Zn at maximum EU regulation levels (20 and 100 ppm of Cu and Zn, respectively; REG), a second diet without any Cu and Zn supplementation (5 ppm Cu, 30 ppm Zn; WS) and a third diet with Cu and Zn at an intermediary level (10 and 50 ppm of Cu and Zn; INT). Cu and Zn were supplemented as Cu2O (CoRouge, Animine) and ZnO (HiZox, Animine), respectively. Eighteen additional finishing pigs (6 per diet) were raised in digestibility cages for excreta collection over 10 d, and their feces were submitted to two types of manure treatment: anaerobic digestion (AD) and composting with straw. Over the entire experimental period, the dietary Cu and Zn content did not influence growth performance of pigs. The Cu and Zn concentrations of the feces decreased linearly (P < 0.001) with dietary content from 191 and 834 (REG) up to 63 and 359 (INT) and 40 and 213 (WS) mg Cu and Zn/kg dry matter (DM) respectively. After both manure treatments, the degradation of the organic matter resulted in a significant increase (twice as much) in Cu and Zn concentration per kg of DM. Feeding strategy appears to be the main lever to reduce the Cu and Zn content of effluents. However, in the context of the diversification of manure management strategies, it is also important to take into account the effect of the effluent collection and treatment chain (e.g., spreading of raw slurry, phase separation, anaerobic digestion, composting), which has also an impact on the behavior of Cu and Zn and consequently on the risk for the environment.

Brazilian Corn Ethanol Coproducts for Pigs: Feeding Value and Blood Parameters.

This study aimed to determine the values of net energy (NE), digestible energy (DE) and metabolizable energy (ME) and digestibility coefficients of corn ethanol coproducts produced in Brazil and their effects on the nitrogen balance and blood parameters of pigs. Ten barrows were housed in metabolic study cages for total collection and fed a reference diet (RD) or 800 g/kg RD + 200 g/kg of a coproduct of corn ethanol. Distiller's dried grains with solubles (DDGS), corn bran with solubles (CBS), distiller's dried grains (DDG) and high-protein distiller's dried grain (HPDDG) were evaluated. The experimental design was randomized blocks with three repetitions per period, totaling six repetitions per diet. Diets containing the HPDDG had greater DE and ME than those containing CBS and DDGS and greater DE than those containing the DDG (p < 0.05). HPDDG, DDG, CBS and DDGS showed 4498, 3419, 3029 and 3335 kcal/kg DE; 4366, 3305, 2934 and 3214 kcal/kg ME; and 2515, 1938, 1649 and 1725 kcal/kg NE, respectively. Pigs fed diets containing HPDDG and CBS showed greater nitrogen retention efficiency than pigs fed DDGS (p < 0.05). Pigs fed diets containing HPDDG had higher blood urea levels than pigs fed CBS and RD, while triglyceride levels in animals that received the CBS diet were greater than those in animals that received all other diets. The HPDDG had the highest energy levels and the best digestibility coefficients. The chemical composition of coproducts influences the nitrogen balance and circulating levels of urea and triglycerides in pigs.

Enteroparasites and risk factors for infection in native and exotic domiciled birds in the North Pioneer region of Paraná State, Brazil

Although parasitic infections are common in free-ranging birds, they pose more significant threats in captivity. Free-ranging birds can live in large areas and have low exposure to parasitosis. On the other hand, birds kept in captivity, the high population density results in greater exposure, putting the animal's survival at risk. The aim of this study was to assess the occurrence of gastrointestinal endoparasites in domiciled birds (native and exotic) in the Mesoregion North Pioneer of Paraná. For this, 59 fecal samples were collected from 63 birds and analyzed by the centrifugation-flotation method in hypersaturated sucrose solution. Of the 63 birds, 38 (60%) were native, 22 (35%) exotic and 3 (5%) hybrids. Oocysts, eggs and larvae were found in 22.03% (13/59) of the samples analyzed. Higher occurrence of protozoa (20.34% - 12/59) than helminths (5.08% - 3/59) was observed, in which seven genera found: Isospora, Eimeria, Ancylostoma, Heterakis, Strongyloides, Cryptosporidium and one cestode. No endoparasites were found in the ten exotic birds and three native birds analyzed. It is concluded that the birds were infected by helminths and protozoa with a higher occurrence of coccidia, with the genus Isospora predominating. Probably due to the low sampling, there was no influence of keeping birds in individual cages compared to birds kept in collective cages, birds raised in rural or urban areas, nor of the adequacy and hygiene of drinkers and feeders, thermal comfort and hygiene of the birds' enclosures. Studies on parasites in wild birds are necessary to gain a more profound understanding of the intensity of anthropogenic influences on these animal species.

Effect of housing systems on behaviour and growth performance in fattening rabbits

This study was conducted to investigate different housing systems and their effects on the growth performance and behaviour of fattening rabbits. The 120 animals were randomly allocated into 3 treatment groups based on the type of housing, from 35 to 84 days: cages (CG), 10 collective wire cages; each housing, 4 animals in 0.3 m²; closed pens (CP), 10 closed pens accommodating 4 rabbits, each with 0.525 m² and straw bedding on the ground; and an open-air system (OA), with 2 pens in the field each measuring 80 m², housing 20 rabbits in each pen. Live weight and feed intake were monitored every week. At the ages of 70 and 84 days, 10 rabbits per treatment were slaughtered, and blood samples were collected to measure haematocrit, cortisol and corticosterone levels. At the same age, 10 additional rabbits per treatment were chosen for an open field test. Compared with CG rabbits, OA rabbits exhibited a significantly lower final weight (2563 g vs. 2980 g). Compared with CG rabbits, OA rabbits also demonstrated reduced weight gain (33.1 vs. 41.8 g/d) and a decreased intake of pelletized feed (111.5 vs. 139.6 g/d). Corticosterone and haematocrit levels were smaller in other lodgements than in caged rabbits, which may suggest a poorer wellbeing status. This study indicated that animals housed in the outdoor system travelled greater distances (P&lt;0.05) than did those housed in other housing types. The choice of rabbit housing during the growing period has an impact on growth performance, which is compromised in the outdoor system, and behaviour, which is negatively affected in the cage system.

Dapagliflozin Stimulates Renal Ammonia Excretion in Rats

Sodium-glucose cotransporter 2 (SGLT2) inhibitors are drugs that induce glycosuria and are used to treat type 2 diabetes mellitus, moreover it has also been used in other conditions such as heart failure and atherosclerosis. However, little is known about the effects of these drugs on renal function. Considering that the maintenance of acid-base balance is closely related to renal physiology, in this study we evaluated the influence of chronic use of dapagliflozin on global renal function and urinary excretion of ammonia and titratable acids. Objective: To evaluate global renal function and urinary acid excretion (ammonia and titratable acid) in male Wistar rats chronically treated with dapagliflozin. Methods: 3-month-old male Wistar rats were randomized to control (C) and dapagliflozin (D) groups. Animals in group D received dapagliflozin (3 mg/kg, gavage) for 4 weeks. All animals were given food and water ad libitum throughout the experimental protocol. At 4 months of age, animals were placed in metabolic cages for 24-hour urine collection followed by blood sampling. Plasma concentrations of creatinine, sodium, potassium, urea, pH, pCO2, and bicarbonate were evaluated. The following were also evaluated: body weight, water intake, urine flow, and excretion of ammonia, titratable acids, glucose, and protein. Protocol approved by CEUA-UNIFESP number: 5985180423. Values expressed as mean ± standard error; number of animals per group: 6. Results: No significant changes were observed in blood gas parameters: pH (C: 7.33±0.043; D: 7.36±0.027), pCO2 (C: 53.30±2.40; D: 52.67±3.63 mmHg) and HCO3− (C: 27.07±1.31; D: 29.75±1.72 mEq/L) and no significant changes in plasma creatinine concentration (C: 0.41±0.04; D: 0.40±0.04mg/dl), Na+ (C: 144±0.47; D: 137±2.04 mmol/l) and K+ (C: 4.30±0.21; D: 4.16±0.20 mmol/l). We observed a significant increase in urine flow (C: 0.027±0.006; D: 0.068±0.005 mL/min/kg), possibly associated with intense glycosuria (C: 0.017±0.005; D: 8.97±0.51 g/24h). The significant increase in plasma urea concentration (C: 39.17±2.57; D: 48.83±1.27 mg/dL) and proteinuria (C: 11.04±0.30; D: 15.79±0.56 mg/24h) may indicate some renal impairment. Considering the marked increase in urinary excretion of ammonia (C: 0.65±0.05; D: 3.49±2.31 mEq/24h) and titratable acids (C: 0.180±0.036; D: 0.628±0.078 mEq/24h), we can conclude that the drug-induced glycosuria may lead to biochemical adaptations to maintain blood glucose levels within the normal range, at the expense of increased metabolic acid production. However, further experiments are needed to confirm this hypothesis. CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

The Nutritional Value of Biowaste Bovine Slaughterhouse Meals for Monogastric Species Feeding: The Guinea Pig as an Animal Model.

Biowaste from slaughterhouses can be recovered to benefit food security and reduce contamination potential. More than 3 billion heads of livestock are consumed worldwide, which will increase by 17% by 2028, generating more biowaste, increasing infectious agents, and causing economic losses due to circular economy principles not being applied. This work evaluated the nutritional quality of four types of biowaste from bovine slaughter which were transformed into a meal for guinea pigs (rumen content (RCM), ears (EaM), blood (BM), and cheeks (CM)) according to their chemical composition, digestible components, energy contribution, and voluntary consumption. For the animal model, adult male guinea pigs were arranged in metabolic cages for feces collection without urinary contamination. Nine guinea pigs were used in each digestibility test. First, a direct digestibility test was conducted using a meal of barley as a reference diet (RD), the indigestibility coefficient of which allowed for the estimation of the digestibility of biowaste meals through indirect calculations; for this, diets composed of 80% of the RD and 20% of the corresponding biowaste meals were evaluated. The difference method was suitable for determining the digestibility of beef biowaste using the indigestibility coefficients of the reference diet to calculate the digestibility of ingredients which could not be offered as 100% of the meal but were incorporated as 20%. The digestible protein and metabolizable energy contents of RCM, EaM, BM, and CM were 10.2% and 2853 kcal/kg, 44.5% and 3325 kcal/kg, 70.7% and 2583 kcal/kg, and 80.8% and 3386 kcal/kg, respectively. The CM and BM feeds had the highest contributions of digestible protein due to their higher nitrogen content, and the CM and EaM feeds had the highest ME contents due to their higher fat contents. The biowaste meal consumption in descending order was CM > RCM > EaM > BM, which were consumed without problems. These results are indicative that these components can be part of guinea pigs' diets, and it is recommended to continue studies into guinea pig growth and fattening diets with different levels of these biowaste meals.

Nutrient intake and digestibility of West Africa Dwarf rams fed basal diet supplemented with multi-nutrient block

Thirty-five (35) West African Dwarf rams (WAD) with an average weight of 13.60+0.2 kg were used to evaluate nutrient intake and digestibility of WAD rams fed basal diet supplemented with multi-nutrient block in a Completely Randomized Design. Multi-nutrient blocks were compounded containing varying levels of Corn Bran (CB) substituting Molasses (M) with CB 0:M 0 %, CB 10 %; M 20 %, CB 20 %; M 10 %, CB 30 %; M 0 % and CB 0 %: M 30 % as treatments 1,2,3,4 and 5 respectively. The trial lasted for fourteen (14) weeks. After the feeding study, the animals were allotted into metabolic cages for separate feeding, faecal and urine sample collection for digestibility trial of WAD rams. The basal diet fed was (Megathyrsus maximus). Data collected data were analyzed using a one-way analysis of variance (ANOVA). The results obtained showed that multi-nutrient feed block did not significantly affect nutrient intake (p&gt;0.05). The dry matter intake of the basal diet (Megathyrsus maximus) ranged from 278.81–326.66 g/day and varied significantly across dietary treatments (p&lt;0.05). Multi-nutrient supplementation had a positive significant (p&lt;0.05) effect on all nutrient digestibility parameters. The digestibility of dry matter ranged from 88.94 to 90.44 %, crude protein from 79.92 to 86.26 %, and neutral detergent fiber from 64.42 to 78.57 %. Based on this recent finding, a multi-nutrient feed block supplemented to a basal diet (Megathyrsus maximus) has no significant influence on nutrient intake but has the potential to be utilized to feed ruminants during the dry season for higher feed utilization of WAD rams

Chronopharmacology of diuresis via metabolic profiling and key biomarker discovery of the traditional Chinese prescription Ji-Ming-San using tandem mass spectrometry in rat models

BackgroundJi-Ming-Shan (JMS) is a traditional prescription used for patients with rheumatism, tendons swelling, relief of foot pain, athlete's foot, diuresis, gout. Although many studies have investigated the active compounds in each herb, the functional mechanism behind its therapeutic effect remains unclear. Study designMetabolic cages for sample collection. The serum components obtained from the experimental animals were analyzed using LC-MS/MS. Furthermore, cross-analysis using the software MetaboAnalyst and Venn diagrams were used to investigate chronopharmacology of JMS in the animal models. PurposeThe aim of this study is to analyze the diuretic effects of JMS and to explore their chronopharmacology involved in organ regulation through four-quarter periods from serum samples of rat models. MethodsMetabolic cages were used for collecting the urine samples and PocketChem UA PU-4010, Fuji DRI-CHEM 800 were used to examine the urine biochemical parameters. The serum components were identified through ultra-performance liquid chromatography-quadrupole time-of-flight (UPLC-Q-TOF) with a new developed method. Cross analysis, Venn diagram, MetaboAnalyst were used to investigate the key biomarker and major metabolism route with the oral administration of the drug. ResultJMS significantly changed the 6 h urine volume with no observed kidney toxicity. Urine pH value ranges from 7.0 to 7.5. The chronopharmacology of JMS diuresis activity were 0–6 and 6–12 groups. UPLC-Q-TOF analyses identified 243 metabolites which were determined in positive mode and negative mode respectively. With cross analysis in the Venn diagram, one key biomarker naringenin-7-O-glucoside has been identified. Major metabolic pathways such as 1: Glycerophospholipid metabolism, 2: Primary bile acid biosynthesis, 3: Sphingolipid metabolism, 4: Riboflavin metabolism, 5: Linoleic acid metabolism, 6: Butanoate metabolism. ConclusionJMS significantly changed the urine output of animals in the 0–6 and 6–12 groups. No change in urine pH was observed and also kidney toxicity. A new UPLC-Q-TOF method was developed for the detection of the metabolites of JMS after oral administration. The cross analysis with Venn diagram and identified the key biomarker of JMS namely naringenin-7-O-glucoside. The results showed that six major pathways are involved in the gastrointestinal system and the liver. This study demonstrated the capability of JMS prescription in the regulation of diuresis and identified a key biomarker that is responsible for its therapeutic effect.

Abstract 063: Pregnancy Protects Aged G Protein-coupled Estrogen Receptor 1 Knock-out Mice Against Hypertension

Hypertension, a major cause of premature death worldwide, is more prevalent in postmenopausal women compared to premenopausal women. Data implicate a protective effect of G protein-coupled estrogen receptor 1 (GPER1) in cardiovascular diseases. A recent study showed that previous pregnancy lowers blood pressure in hyperandrogenemic rats. We hypothesized that pregnancy protects against hypertension elicited in aged female mice lacking GPER1. 16-20 month-old GPER1 wild-type (WT) and knock-out (KO) mice with or without a history of former pregnancies were implanted with telemeters for blood pressure recording and placed in metabolic cages for 24h urine collection. Plasma, adrenal glands and kidneys were collected. GPER1 deletion increased mean arterial pressure in virgin mice (125±3 vs. 109±2 mmHg; n=3,7; p=0.0005), and previous pregnancies (PP) eliminated this genotypic effect (106±1 mmHg; n=6; p≤0.0001). Aldosterone plays a critical role in blood pressure regulation, we measured its urinary excretion and revealed lower levels in PP KO mice compared to virgin KO mice (4.8±0.8 vs. 13.0±3.0 pg/day; n=6; p=0.0099). PP KO mice elicited greater levels of circulating estradiol levels compared to virgin KO mice (42.8±5.2 vs. 29.5±3.4 pg/mL; n=8,6; p=0.0451). To explore the role of adrenal estrogen receptors (ER) in regulating aldosterone production, we assessed the adrenal expression of ER and CYP112B, the gene coding for aldosterone synthase. No difference was observed in ERα, however ERβ expression was higher in PP KO mice compared to virgin KO mice (2.4±0.3 vs. 1.1±0.1 fold change; n=6,5; p=0.0359). GPER1 deletion increased CYP112B expression in virgin mice (2.0±0.4 vs. 1.0±0.2 fold change; n=7,5; p=0.0265), and this was eliminated with PP (0.9±0.2 fold change; n=5; p=0.0260). Aldosterone regulates renal epithelial sodium channel (ENaC), so we assessed its subunits’ expression. Renal ENaCα and ENaCβ increases with the deletion of GPER1 in the virgin group, and this effect was lost with PP. ENaCγ withheld the same trend, but it did not reach significance. Overal, our data suggest that GPER1 and former pregnancy protect from hypertension in aged females at least partially via regulating aldosterone and ENaC signaling.

#6153 SODIUM-GLUCOSE COTRANSPORTER 2 INHIBITORS VERSUS DIPEPTIDYL PEPTIDASE 4 INHIBITORS AS STABILIZERS OF HIF PATHWAY IN DIABETIC NEPHROPATHY RATS

Abstract Background and Aims With the diabetes pandemic, chronic kidney disease is a burden, with diabetic nephropathy (DN) being the primary leading cause of end-stage renal disease. Antidiabetic drugs have shown renoprotective effects via different mechanisms, and among those are SGLT2 inhibitors and DPP-4 inhibitors. Hypoxia-inducible factor (HIF) pathway, a significant contributor to inflammation development in the kidneys, is a major pathway that regulates erythropoietin synthesis. Prolyl hydroxylase domain (PHD) decreases erythropoietin synthesis by inhibiting HIFs. PHD inhibitors are anticipated to have additional effects, such as protection against metabolic diseases, due to HIF's impact on many genes. The diabetic kidney is characterized by enhanced HIF-1α activation but decreased HIF-2α activity. These actions may significantly contribute to glomerular and renal tubular dysfunction, renal inflammation and fibrosis, and decreased erythropoietin synthesis observed in DN. This work aims to test the renoprotective effect of SGLT2 inhibitors and DPP-4 inhibitors by controlling the proinflammatory and anti-inflammatory domains of the HIF pathway. Method Type 1 DM rat model was induced in 24-hour-fasted Sprague Dawley rats by a single intraperitoneal injection of 45 mg/kg streptozotocin (STZ). DM was verified by measuring blood glucose seven days following STZ injection, and only animals with glucose levels of ≥15 mM were included (n = 24), randomly and equally distributed, then received either saline or vildagliptin (3 mg/Kg) or empagliflozin (30 mg/Kg) once daily by oral gavage for three months. An additional group was used as a non-diabetic control. At the end of the experiment, rats were placed in metabolic cages for 24-h urine collection, then sacrificed. Blood samples and kidney tissue were collected. Kidney function was assessed by measuring serum creatinine and urinary albumin: creatinine ratio. HIF1α, HIF2α, and PHD3 mRNA expression in kidney tissues were assessed using quantitative real-time PCR, and to indirectly assess HIF2α protein stability, immunohistochemical staining for PHD3 was also performed. Results Vildagliptin and empagliflozin could significantly ameliorate the diabetic disturbance of renal function, as demonstrated in serum creatinine (F = 23.518, p&amp;lt;0.001) with a non-significant difference between both treated groups, and in the significantly reduced albumin/creatinine ratio (F = 14.453, p&amp;lt;0.001), with a significantly lower ratio for empagliflozin (4.73±0.54) than vildagliptin-treated group (9.09±1.04). Regarding the HIF pathway as a potential mechanism, empagliflozin-treated groups showed a significantly higher HIF2α gene expression in kidney tissue samples (0.98±0.10) than the vildagliptin-treated group (0.58±0.05). For the expression of its regulator, PHD3, there was a significant difference between groups (F = 5.694, p = 0.005). However, the vildagliptin-treated group (0.65±0.06) didn′t differ significantly from the untreated group (0.60±0.03), in contrast to the empagliflozin-treated group (2.01±0.50), which showed a significantly higher expression than the other groups (Figure 1). Conclusion Empagliflozin significantly increased the level of HIF-2α in renal tissue. In addition, it nearly neutralizes the tubular expression of PHD3 compared to non-treated and vildagliptin-treated rats. SGLT2 inhibition is effective for correcting the proinflammatory/anti-inflammatory imbalance in DN.

Chronic circadian disruption impairs cardiovascular rhythms and leads to kidney disease in mice

Shift workers have an increased risk of developing hypertension and reduced kidney function. Disruption of behavioral or environmental circadian rhythms increases cardiometabolic disease risk in humans and animals. We hypothesized that chronic circadian disruption (CCD) impairs cardiovascular rhythms and increases renal injury markers. Male C57BL/6J mice starting at 8-week of age were maintained under a normal light/dark cycle (12-h light, 12-h dark, control) or a CCD protocol (10-h light, 10-h dark, T20) with ad libitum food and water for 10 weeks. T20 mice gained significantly more body weight compared to control mice. Control mice showed a diurnal variation in food intake, while T20 mice had similar food intake during both light and dark phases with more food consumed in the light phase compared to control mice. Mean arterial pressure (MAP), heart rate (HR), and locomotor activity were measured by telemetry after 10 weeks of CCD. MAP between the light and dark periods was significantly different in control mice (12:12 LD), while T20 mice (10:10 LD) lacked diurnal variation (control 119±3 vs.101±2 mm Hg, dark vs. light, respectively, p&lt;0.001; T20 114±13 vs.113±12 mm Hg, dark vs. light, respectively, p=0.86; n=3-4). Control mice showed a diurnal variation in HR, whereas T20 mice did not show a light-dark difference (Control- 584±11 vs. 511±4 bpm, dark vs. light, respectively, p=0.001; T20- 537±14 vs. 526±5 bpm, dark vs. light, respectively, p=0.48; n=3-4). Dark phase HR was significantly decreased in T20 mice (p=0.01, control vs. T20). Control mice had a light-dark difference in activity, while T20 mice lacked diurnal variation in activity with significantly higher activity during the light phase (p=0.04, control vs. T20). Mice were placed in metabolic cages for urine collection during the light (control: ZT0-12; T20: ZT0-10) and dark (control: ZT12-0; T20: ZT10-0) phases. Urinary excretion of renal tubular injury markers albumin, neutrophil gelatinase-associated lipocalin (NGAL), and kidney injury molecule-1 (KIM-1) were measured (ELISA). Control mice had significantly higher albumin and NGAL excretion in dark vs. light phases, while T20 mice lacked a significant diurnal pattern with significantly elevated albumin and NGAL during the light phase compared to control mice (albumin: control 1.00±0.23 vs. 0.09±0.05 ug/hr dark vs. light, p=0.04, control light vs. T20 light, p=0.04; NGAL: control 1410±223 vs. 89±58 pg/hr dark vs. light, p=0.02, control light vs.T20 light, p=0.04, n=4-6). CCD also blunted the diurnal rhythm of KIM-1 excretion (light cycle, p=0.04, n=3-6). The diurnal variation in sodium and potassium excretion was also lost in T20 mice. These results indicate that CCD impairs cardiovascular rhythms as well as diurnal excretion of electrolytes and renal injury markers, which may increase risk for kidney disease. P01HL136267, AHA 856877 This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

The effect of chronic unpredictable stress on renal mitochondrial function in female mice

Background: Chronic stress can induce high blood pressure and lead to decreased renal function by mechanisms that remain unclear. The exposure of rodents to chronic unpredictable stress (CUS) is a translational model used for investigating the physiological impact of stress. The CUS protocol consists of unpredictable and random stressors that mimic real life exposure to stress. While stress is known to impact mitochondrial function, little is understood about the direct impact of chronic stress on renal mitochondrial respiration. Moreover, while studies have shown a link between estrogen and mitochondria through estrogen receptors, the relation between stress induced renal mitochondrial dysfunction and estrous cycle is unknown. Hypothesis: Exposing female mice to CUS will increase blood pressure and cause decreased renal mitochondrial respiration. Methods: We exposed adult female C57BL/6 mice to CUS for 28 days. Before and after stress, all control (CON, n=8) and CUS (n=10) mice were placed in metabolic cages for overnight urine collection. Urine albumin was measured by dipstick assay. On day 28, mice were assessed for blood pressure measurement via tail cuff. 24 hours later, mice were euthanized, and vaginal lavage was performed. The left kidney was removed, transected into thirds, and the poles were placed in relaxing buffer. Kidney mitochondrial oxygen consumption was assessed using high-resolution respirometry. Results: Data were stratified by phases of the estrus cycle. Neither blood pressure nor urinary albumin was significantly altered by CUS in stressed females. Females in estrus and proestrus exposed to CUS (n=5) exhibited a decrease of 20.8% ± 5.1 (n=5, p=0.03) in renal mitochondrial maximal uncoupled respiration compared to non-stressed CON. Renal mitochondrial respiration in diestrus was similar between CUS and CON. Conclusion: Results from this study reveal a link between the female estrus cycle, stress, and mitochondrial function. This work was supported by NIH grants P20GM109091 (F.H.), R01HL130972-01A1 (F.G.S.), R01HL5949 (F.G.S.), RO1DK132948 (C.W. &amp; F.P.) and R01 MH129798 (SKW); VA grants: VISN7 RDA (F.H.), Merit awards: BX000168-10A1 (F.G.S.), BX005320 (F.G.S.), and BX002604 (M.J.R.). This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

The sustainability status and the development strategy of collective cage-based beef cattle smallholder farming on Lombok Island: the dimension of disease incidence

The incidence of the disease is one of the problems faced by beef cattle farms in Lombok Island, West Nusa Tenggara Province in increasing the production and productivity of livestock. On smallholder livestock, beef cattle are maintained intensively using a collective cage group, making it easier to manage and promote them. This aim is to analyze the status of the sustainability of the development of beef cattle smallholder farming based on collective cages in Lombok Island from the dimension of disease incidence. The method used to determine the sustainability status is Multi-Dimensional Scaling (MDS) with the Rapid Appraisal Beef Cattle Diseases (RAPBCD) approach of 20 diseases as attributes. The sensitive attributes that affect the sustainability index and the effect of errors are determined based on the Leverage analysis and Monte Carlo test. The results of the sustainability analysis showed that the status of the dimensions of the disease incidence dimension was 56.38%. The analysis results of the 20 diseases as attributes studied, 9 diseases (diarrhea, scabies, flatulence, itching, demodec, pink eye, anthrax, reproductive, epizootic septimea) are sensitive attributes and need to be improved because they will affect increasing the value of the sustainability index. Determination of the key factors of sustainability is obtained by prospective analysis to determine the future strategy for the development of collective cage-based beef cattle smallholder farming. The conclusion is that the status of the sustainability of the development of collective cage-based beef cattle smallholder farming on Lombok Island from the dimension of disease incidence is in a fairly sustainable category with four recommended development strategies, namely: strategies to improve beef cattle health management; increasing access to information and livestock health technology; increasing the role of the government, businessmen, and other stakeholders and strengthening farmer institutions, farmer economic institutions.

Diuretic and Natriuretic Effects of Hesperidin, a Flavanone Glycoside, in Female and Male Hypertensive Rats

Hesperidin (HSP) is a major flavanone glycoside in citrus fruits, including sweet oranges and lemons. It demonstrates numerous pharmacological activities, such as antihypertensive effects and cardiac and kidney tissue protection. However, its effect on modulating renal function has yet to be properly explored. Female and male Wistar spontaneously hypertensive rats (SHR) were used to test the effect of HSP on renal function. The rats were divided into different groups, treated orally, and placed in metabolic cages for urine collection for 8 h. HSP, at doses of 0.3-3 mg/kg, led to an increase in urine volume in both female and male SHR. This effect was associated with increased Na+ elimination (3 mg/kg) without causing any change in K+ excretion or pH and conductivity values. When given HSP in combination with hydrochlorothiazide (HCTZ) or amiloride (AMLR), urine volume and Na+ elimination were significantly increased compared to the group that received only HSP. In relation to K+ excretion, the depleting effect of HCTZ and the sparing of AMLR prevailed in both groups. Pre-treatment with a non-selective cholinergic receptor antagonist, atropine, partially prevented HSP-induced diuresis and natriuresis in male SHR, but this effect was not demonstrated with the non-selective inhibitor of the enzyme cyclooxygenase, indomethacin. This study shows the diuretic action of HSP in hypertensive rats, an activity probably associated with the cholinergic pathway. Although various biological actions have already been defined for HSP, this pioneering research reveals its potential as a diuretic medicine.

Abstract P073: Long-term Augmentation Of Acetylcholine Bioavailability Halts The Progression Of Lupus Hypertension

Renal inflammation promotes hypertension in systemic lupus erythematosus (SLE). Our recent studies suggest that renal inflammation is regulated by the vagally-mediated cholinergic anti-inflammatory pathway, and that vagal tone is reduced in SLE mice. We found that augmenting central bioavailability of acetylcholine via the acetylcholinesterase inhibitor, galantamine, increases vagal tone and reduces renal inflammation and mean arterial pressure (MAP) in SLE mice after two weeks. However, the long-term efficacy and therapeutic potential of galantamine are unknown. Thus, we hypothesized that chronic galantamine administration would effectively halt the progression of SLE hypertension and renal injury. Starting at 20 weeks of age, female SLE ( NZBWF1 ) and control ( NZW ) mice received galantamine hydrobromide (3 mg/kg/day, SQ) or vehicle continuously for 16 weeks via osmotic minipump. At 35 weeks, mice were placed in metabolic cages for urine collection, carotid catheters were implanted to assess MAP in conscious mice, and tissues were harvested. MAP (mmHg, n=4-6) was higher in SLE mice than controls (161.9±9.9 vs. 128.3±0.9, p=0.001) and long-term galantamine treatment prevented further increases in MAP in SLE mice (161.9±9.9 vs. 138.3±4.9, p= 0.01). Survival rate was lower in SLE mice compared to controls (50% vs. 100%) and galantamine improved survival to 70% in SLE mice. Eighty percent (4 of 5) of SLE mice had urinary albumin over 300 mg/dL and chronic galantamine lowered the prevalence to 57% (4 of 7); no controls had albuminuria. There was no difference in CD3+CD4+ T cells amongst groups, but the percentage of renal CD3+CD8+ T cells was increased in SLE mice compared to controls (29.7±2.2 vs. 12.8±0.79, p&lt;0.0001, n=4-7) and galantamine reduced this percentage in SLE mice (29.7±2.2 vs. 22.9±1.2, p=0.0261). Taken together, our data indicate chronic augmentation of central acetylcholine bioavailability is protective against SLE hypertension since it improves survival rate, decreases renal injury and alters cytotoxic renal immune cell populations. These data further support acetylcholinesterase inhibition as a novel therapeutic option for hypertension associated with autoimmunity.

THE DESIGNING EXPERIMENT OF ESSENTIAL HYPERTENSION: THE CHOICE OF A CONTROL GROUP FOR SPONTANEOUSLY HYPERTENSIVE RATS

Objective: The spontaneously hypertensive rat (SHR) is the most widely studied animal model of essential hypertension. The Wistar-Kyoto rats (WKY) were originally bred as normotensive controls for the SHR, while the Wistar (WIS) strain is generally the most popular in research. The objective of the study was to check whether Wistar could be used as controls for SHR by comparing blood pressure levels in three groups of animals. Design and method: Adult male WIS (n = 5), WKY (n = 6), and SH (n = 4) rats, 20th week of age, were used. The animals were housed in the Animal Research Center of the Lithuanian University of Health Sciences under permission No. G2–137. They were kept in collective cages and allocated in a controlled environment with a light/dark cycle (12/12 h), the temperature at 22 ± 2C, and had free access to food and water. Following animal sedation, heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were measured using the on-invasive method of tail-cuff (AD Instruments IN125/R NIBP system, UK and LabChart software). Each measurement was performed ten times, and the median value was used. All measurements were performed by the same researcher in a quiet environment. Mean arterial pressure (MAP) was calculated by the following equation: DBP+1/3(SBP-DBP). The Kruskal-Wallis test was used to determine group differences. The Mann-Whitney test was used for two groups comparisons. Results: SHR BP values were highest, WKY - in the middle, and WIS - the lowest. Measured parameters differed statistically significantly between the three rat groups (p &lt; 0.05) (Table 1). The two groups comparison revealed that all parameters in SHR had statistically significant differences between the WKY as well as WIS (p &lt; 0.05), except HR in WIS. HR did not differ between SHR and WIS rats (p = 0.190). Comparing WKY and WIS groups, there was no significant difference between SBP (p = 0.284), DBP (p = 0.524), MAP (p = 0.354), except HR, which was significantly higher in WIS (p = 0.002). Conclusions: Adult spontaneously hypertensive rats have significant arterial hypertension. Blood pressure measurements of Wistar-Kyoto and Wistar rats do not differ, so both of them can be used as controls for hypertensive rats.

Kynurenine Infusion Disrupts Normal Blood Pressure Circadian Rhythms

Kynurenine is the first stable product of tryptophan metabolism, and its level increases with age. Elevated kynurenine/tryptophan ratios have been implicated in many aging‐related diseases including chronic kidney disease (CKD). We hypothesized that chronic infusion of kynurenine would induce alterations in renal‐related parameters, such as blood pressure, sodium excretion and glomerular filtration rate (GFR), that could contribute to development of age‐related CKD. In an IACUC‐approved study, three‐month‐old male Sprague Dawley rats were instrumented with aortic and venous catheters, as well as telemeters for blood pressure monitoring, and then housed in metabolic cages for urine collection. Following a five‐day control period, rats received continuous kynurenine infusion (5 mg/kg, 10 mg/kg, 50 mg/kg) or vehicle for 4 weeks. We found that GFR decreased after 2 weeks of KYN treatment [1.29 (n=5) vs. 1.51 (control, n=16) or 1.50 (vehicle, n=3) mL/min p=0.04]. The normal circadian rhythm for blood pressure was disrupted by all doses of kynurenine while heart rate maintained its normal diurnal pattern. Mean arterial pressure in kynurenine‐treated rats tended to increase over time compared to vehicle‐treated. Kynurenine infusion also induced increased water consumption. These data suggest that kynurenine treatment impacts renal function and may contribute to the development of CKD. Non‐dipping blood pressure is a significant risk factor for cardiovascular disease, even in the context of normotension. Further studies will be needed to determine the mechanism of this effect.

Central Activation of the Cholinergic Anti‐Inflammatory Pathway Improves Outcome in a Murine Model of Systemic Lupus Erythematosus

The cholinergic anti‐inflammatory pathway is an endogenous vagus‐to‐spleen mechanism that regulates the immune system and when activated, results in decreases in systemic inflammation. Previous studies from our group demonstrated that the pharmacological potentiation of the efferent vagus nerve via systemic administration of galantamine reduces renal inflammation and blood pressure in systemic lupus erythematosus (SLE), suggesting an impairment in the cholinergic anti‐inflammatory pathway in this model. In this study, we aimed to delineate specific pathways and we hypothesized that central stimulation of vagal efferents by selective activation of neurons within the dorsal motor nucleus of the vagus (DMVN) would similarly protect SLE mice and confirm the role of the cholinergic anti‐inflammatory in controlling inflammation. For that, we selectively activated DMVN neurons using designer receptors exclusively activated by designer drugs (DREADDs). Female NZBWF1 (SLE) and parental control – NZW (Control) mice (n=3‐8) received bilateral microinjections of pAAV‐hSyn‐hM3D(Gq)‐mCherry or pAAV‐hSyn‐mCherry (control virus) into the DMVN at 31 weeks of age. Two weeks post‐microinjection, DREADD agonist CNO (3mg/kg) was administered subcutaneously for 2 weeks starting at 33 weeks. At 35 weeks, mice were housed in metabolic cages for urine collection and catheters were implanted in the carotid to access mean arterial pressure (MAP) in conscious mice. Mice were subsequently euthanized, spleen was collected for Western blotting, blood for double‐stranded (ds) DNA autoantibody quantification and brain to confirm the site of virus microinjection. Selective activation of DMVN neurons did not alter MAP (mmHg) in SLE mice (SLE: 146 ± 6 vs SLE/Gq DREADD: 142 ± 3) or controls (Control: 126 ±4 vs Control/Gq DREADD: 132 ± 2), and also did not change dsDNA autoantibodies (activity units) in SLE mice (SLE: 4.7e5± 1.1e4 vs SLE/Gq DREADD: 3.7e8 ± 1.3e6) or controls (Control: 1.8e5± 5.3e4 vs Control/Gq DREADD: 2.8e5± 1.3e5). Splenic TNFα protein expression was increased in SLE mice compared to controls (SLE: 1.9e6 ± 3.6e5 vs Control: 6.5e5 ± 8.6e4, p=0.001) and DMVN neuron activation decreased splenic TNFα expression in SLE mice (SLE: 1.9e6 ± 3.6e5 vs SLE/Gq DREADD: 1.1e6 ± 1.1e5, p=0.05) but not controls (Control: 6.1e6 ± 3.1e6 vs Control /Gq DREADD: 1.7e6±4.4e5). Albumin excretion rate (µg/day) was higher in SLE mice compared to controls (SLE: 10210±4015 vs Control 97.1±54.3, p=0.07) and DMVN neuron stimulation decreased albumin excretion rate in SLE mice although not significantly (SLE/Gq DREADD: 207.4±142.1, p=0.07). In addition, selective activation of DMV neurons decreased urinary leukocytes (62.5% vs 50%) and blood in the urine (50% vs 16%) in SLE mice. The present study showed that boosting the cholinergic anti‐inflammatory pathway via selective activation of vagal efferents lowered splenic inflammation and protected the kidney without altering blood pressure suggesting an important role of the cholinergic anti‐inflammatory pathway in regulating inflammation and renal injury in SLE.

Abstract 439: Abcg5 Abcg8 Are Essential To Maintain Sterol Balance When Challenged With Dietary Cholesterol In Mice

Background: ABCG5/ABCG8 (G5/G8) is the primary biliary cholesterol transporter and accounts for &gt;70% of biliary cholesterol secretion. Mice and humans maintain fecal cholesterol excretion under a variety of conditions that disrupt biliary cholesterol secretion, indicating the presence of a non-biliary route for cholesterol elimination. Cholesterol can be actively secreted from the intestine, a pathway termed transintestinal cholesterol excretion (TICE). The present study investigates rates of intestinal cholesterol secretion in mice lacking G5/G8 to determine if adaptive responses within the gut facilitate cholesterol excretion in the absence of the primary biliary cholesterol transporter. Methods: Wild-type (WT) and whole body Abcg5/Abcg8 deficient mice (G5/G8 KO) were maintained on a plant sterol free (PSF) diet to prevent the development of experimental sitosterolemia and potential confounding effects of biologically active phytosterols. Mice were anesthetized, the gall bladder cannulated, and the intestine perfused with model bile to simultaneously determine biliary and intestinal cholesterol secretion rates. Sterol balance studies were conducted in mice sequentially maintained on PSF diet, a PSF diet supplemented with 0.2% cholesterol, and standard rodent chow. Mice were allowed to acclimate to each diet for 14 days, then placed on wire-bottom cages for fecal collection. At termination of the experiment, basal bile, plasma, and tissues were collected. Fecal neutral sterols (FNS) were analyzed by GC-MS. Results: Despite a substantial reduction in biliary cholesterol secretion in G5/G8 KO mice, differences in intestinal cholesterol secretion rates were only observed in males, with KO mice excreting less cholesterol into the intestinal lumen. FNS did not differ between genotypes when maintained on the PSF diet. On chow diet, FNS increased 2x in both genotypes, but did not differ across genotypes. When PSF diet was supplemented with 0.2% cholesterol, FNS increased by 3x in WT mice, but were unchanged in G5/G8 KO mice, relative to PSF diet levels. Conclusions: Abcg5/Abcg8 is essential to maintain sterol balance when cholesterol is present in the diet. TICE is unable to compensate for Abcg5/Abcg8 deficiency in cholesterol fed mice.

G Protein‐coupled Estrogen Receptor 1 and Pregnancy Confer Protection against Renal Injury in Aged Female Mice

Chronic kidney disease, which is a leading risk factor impacting 1 in 7 American women, is more frequent in aged compared to younger women. Along with the natural aging process, aged women undergo a decline in circulating estrogen level, which is a predisposing factor for renal disease. Estrogen activates the G protein‐coupled estrogen receptor 1 (GPER1), which elicits cardiovascular and renal protective actions. Additionally, pregnancy augments GPER1‐induced vasodilation in rats. However, there is limited information on the potential interaction between GPER1 and pregnancy in the renal health later in life. We hypothesize that GPER1 signaling, and pregnancy confer protection against renal injury in aged female mice. In our study, 14‐16 months‐old GPER1 knock‐out (KO) and wild‐type (WT) female mice with and without a history of former pregnancies were placed into metabolic cages for collection of 24h urine samples. Then, animals were euthanized, plasma and kidneys were harvested for assessment of renal injury. No significant differences in body weight were observed between groups. GPER1 deletion in virgin mice did not impact food intake or urinary Na+ excretion (UNaV). Former pregnancies reduced food intake (p=0.0003) and UNaV (p&lt;0.0001) in GPER1 KO mice. To assess renal function, we measured urinary albumin excretion and plasma creatinine (Cr). GPER1 deletion increased urinary albumin excretion in virgin mice (KO: 16.47±2.08; WT: 6.06±1.04 μg/day; n=6 &amp; 7 respectively; p=0.0005). Interestingly, prior pregnancies eliminated this genotypic difference in albuminuria (KO: 6.12±1.44; WT: 5.79±1.66 μg/day; n=6 &amp; 8 respectively; p=0.986). GPER1 deletion also resulted in higher plasma Cr level in virgin mice (KO: 1.36±0.08; WT: 0.97±0.05 mg/mL; n=6 &amp; 7 respectively; p=0.0018). Prior pregnancies decreased plasma Cr levels in GPER1 KO mice (0.84±0.10 mg/dL, n= 5; p= 0.0012). We also measured urinary excretion of endothelin (ET‐1) and aldosterone which are causally linked to renal injury. GPER1 KO elicited greater levels of urinary ET‐1 compared to WT virgin mice (0.37±0.06 vs.0.17±0.01 pg/day; n=6 &amp; 7, respectively; p=0.0063). Previous pregnancies lowered urinary levels of ET‐1 and aldosterone in GPER1 KO mice (ET‐1: p=0.0049; aldosterone: p=0.0099). Furthermore, histological assessment of kidney sections revealed diffuse proliferative glomerulonephritis (GN) with intracapillary hyaline/protein thrombi, in GPER1 KO virgin mice only. No significant acute tubular injury was observed in any group. Further experiments will determine blood pressure and characterize the glomerular lesions evident in aged GPER1 KO virgin mice. Overall, our data demonstrate significant glomerular injury (GN), greater plasma Cr and greater urinary levels of albumin and ET‐1 in GPER1 KO virgin mice compared to WT virgin and previously‐pregnant GPER1 KO aged mice. The current data suggest that GPER1 and former pregnancies provide protection against glomerular injury in aged females.