Metabolic Cages Research Articles

Reversible expansion of tissue macrophages in response to macrophage colony-stimulating factor (CSF1) transforms systemic lipid and carbohydrate metabolism.

Macrophages regulate metabolic homeostasis in health and disease. Macrophage colony-stimulating factor (CSF1)-dependent macrophages contribute to homeostatic control of the size of the liver. This study aimed to determine the systemic metabolic consequences of elevating circulating CSF1. Acute administration of a CSF1-Fc fusion protein to mice led to monocytosis, increased resident tissue macrophages in the liver and all major organs, and liver growth. These effects were associated with increased hepatic glucose uptake and extensive mobilization of body fat. The impacts of CSF1 on macrophage abundance, liver size, and body composition were rapidly reversed to restore homeostasis. The effects of CSF1 on metabolism were independent of several known endocrine regulators and did not impact the physiological fasting response. Analysis using implantable telemetry in metabolic cages revealed progressively reduced body temperature and physical activity with no change in diurnal food intake. These results demonstrate the existence of a dynamic equilibrium between CSF1, the mononuclear phagocyte system, and control of liver-to-body weight ratio, which in turn controls systemic metabolic homeostasis. This novel macrophage regulatory axis has the potential to promote fat mobilization, without changes in appetence, which may have novel implications for managing metabolic syndrome.NEW & NOTEWORTHY CSF1 administration expands tissue macrophages, which transforms systemic metabolism. CSF1 drives fat mobilization and glucose uptake to support liver growth. The effects of CSF1 are independent of normal hormonal metabolic regulation. The effects of CSF1 are rapidly reversible, restoring homeostatic body composition. CSF1-dependent macrophages and liver size are coupled in a dynamic equilibrium.

Lipid supplementation with macadamia by-product reduces methane emissions by sheep

Macadamia cake (MC) is a waste product from the macadamia nut industry with high nutritional value for animal nutrition. It has the potential to modify rumen fermentation, increase the efficiency of rumen microorganisms, and reduce methanogenesis. This study aimed to evaluate how the dietary lipid supplementation with MC modulates the methane (CH4) emission and nutrients digestibility of finishing lambs. Thirty-one lambs, approximately 90 days old and mean initial body weight of 26 ± 3.4 kg, were allocated to individual metabolic cages and subjected to in vivo digestibility assays for 24 days (17 days of adaption and 7 days of data collection). The four treatments included a Control group with no MC addition, and three groups with varying amounts of MC inclusion in the diet: 4.5%, 8.5%, and 14% on a dry matter basis. The ruminal content was collected individually at the last day of the digestibility assay 2 to 3 h after the morning feed, to measure pH, protozoan count, and short-chain fatty acids. The animals were then moved to semi-open respirometry chambers for the in vivo measurement of CH4 emission. A completely randomized design was used in the study assuming MC intake (MCI) as fixed effect and each animal as random effect. The variables were submitted to tests of normality and homoscedasticity. The data was submitted to analysis of variance at a 5% significance level using the F test (P < 0.05) and polynomial regression analysis. Pearson’s correlation coefficient test was also applied to all variables. Daily dry matter intake or apparent total tract digestibility parameters were not affected by MCI (P > 0.05), while ether extract and gross energy intake showed the widest range of values, from 0.01 to 0.09 (kg/day) and 9.3 to 22.5 (MJ/day), respectively, increasing (P > 0.05) according to MCI. In addition, total digestible nutrients increased linearly with MC supplementation (P = 0.037). MCI had a significant suppressive effect on enteric CH4 production from 21.9 to 8.6 (L/day) (P < 0.05) and protozoan count (P < 0.001) from 291875 to 69500 (n/mL), while a cubic (P = 0.03) and linear (P = 0.05) effect was observed for ammonia nitrogen and butyric acid, respectively. Macadamia cake may be used as an ingredient in sheep diets and its inclusion up to 14% has shown promise in reducing daily emissions of enteric CH4 without compromising nutrient digestibility and ruminal fermentation, in addition to contributing to reducing the environmental impact by avoiding the disposal of this industrial by-product.

A combination of β-hydroxybutyrate and citrate ameliorates disease progression in a rat model of polycystic kidney disease.

Our research has shown that interventions producing a state of ketosis are highly effective in rat, mouse, and cat models of polycystic kidney disease (PKD), preventing and partially reversing cyst growth and disease progression. The ketone β-hydroxybutyrate (BHB) appears to underlie this effect. In addition, we have demonstrated that naturally formed microcrystals within kidney tubules trigger a renoprotective response that facilitates tubular obstruction clearance in healthy animals but, alternatively, leads to cyst formation in PKD. The administration of citrate prevents microcrystal formation and slows PKD progression. Juvenile Cy/+ rats, a nonorthologous PKD model, were supplemented from 3 to 8 wk of age with water containing titrated BHB, citrate, or in combination to find minimal effective and optimal dosages, respectively. Adult rats were given a reduced BHB/citrate combination or equimolar control K/NaCl salts from 8 to 12 wk of age. In addition, adult rats were placed in metabolic cages following BHB, citrate, and BHB/citrate administration to determine the impact on mineral, creatinine, and citrate excretion. BHB or citrate alone effectively ameliorates disease progression in juvenile rats, decreasing markers of cystic disease and, in combination, producing a synergistic effect. BHB/citrate leads to partial disease regression in adult rats with established cystic disease, inhibiting cyst formation and kidney injury. BHB/citrate confers benefits via multiple mechanisms, increases creatinine and citrate excretion, and normalizes mineral excretion. BHB and citrate are widely available and generally recognized as safe compounds and, in combination, exhibit high promise for supporting kidney health in polycystic kidney disease.NEW & NOTEWORTHY Combining β-hydroxybutyrate (BHB) and citrate effectively slows and prevents cyst formation and expansion in young Cy/+ rats using less BHB and citrate than when used alone, demonstrating synergy. In adult rats, the combination causes a partial reversal of existing disease, reducing cyst number and cystic area, preserving glomerular health, and decreasing markers of kidney injury. Our results suggest a safe and feasible strategy for supporting kidney health in polycystic kidney disease (PKD) using a combination of BHB and citrate.

Apparent nutrient digestibility, metabolizable energy and apparent ileal amino acid digestibility of commercial partially defatted Hermetia illucens meal for laying hens

Abstract A digestibility study with laying hens was carried out to determine the nutritional value of a commercial and representative (batch to batch variance adjusted) insect meal based on Hermetia illucens (HI) larvae, (from black soldier fly) which was the objective in this study. A basal diet (BD; CP 15%), formulated and fed as such and an experimental diet (HD; CP 21%) consisting of BD with inclusion of 18% of the HI meal were used in the study. The BD and HD were fed to eight and six replicate metabolic cages, respectively, with eight Dekalb White laying hens each from 25 to 27 weeks of age. Diets (pelleted with TiO2 as marker) and water were available for ad libitum intake. Excreta was collected during the last three days to determine AMEn and apparent total tract faecal nutrient digestibility coefficients (ATTDC). Distal ileal content was collected at the last day of the experiment to determine apparent ileal amino acids digestibility of diets and HI meal. Using table values for endogenous losses standardised ileal amino acids digestibility coefficient (SIDC) of HI meal were also calculated. Analysed nutrients (g/kg) in HI meal were: 47 moisture, 529 crude protein, 71 ash, 135 fat and thus 218 was calculated as carbohydrates. Determined AME AMEn for HI meal was 3,846 kcal/kg dry matter (DM) and AMEn was 3,498 3,671 kcal/kg DM and ATTDC AFD for crude protein, crude fat and carbohydrates was 0.830, 0.940 and 0.680, respectively. Average SID coefficient for the 18 amino acids was 0.861 86.1%. Among indispensable amino acids SIDC ranged from 0.790% for threonine to 0.950% for phenylalanine and was 0.840% for lysine. These findings highlight that HI meal is an interesting alternative protein source for soybean meal (SBM). Besides market prices and availability, demands for more sustainable poultry production will determine the use of HI meals as alternative for SBM in poultry diets in the near future, especially in regions where SBM is imported from overseas.

Parental cardiorespiratory fitness influences early life energetics and metabolic health.

High cardiorespiratory fitness (CRF) is associated with a reduced risk of metabolic disease and is linked to superior mitochondrial respiratory function. This study investigated how intrinsic CRF affects bioenergetics and metabolic health in adulthood and early life. Adult rats selectively bred for low and high running capacity [low capacity runners (LCR) and high capacity runners (HCR), respectively] underwent metabolic phenotyping before mating. Weanlings were evaluated at 4-6 wk of age, and whole body energetics and behavior were assessed using metabolic cages. Mitochondrial respiratory function was assessed in permeabilized tissues through high-resolution respirometry. Proteomic signatures of adult and weanling tissues were determined using mass spectrometry. The adult HCR group exhibited lower body mass, improved glucose tolerance, and greater physical activity compared with the LCR group. The adult HCR group demonstrated higher mitochondrial respiratory capacities in the soleus and heart compared with the adult LCR group, which coincided with a greater abundance of proteins involved in lipid catabolism. HCR and LCR weanlings had similar body mass, but HCR weanlings displayed reduced adiposity. In addition, HCR weanlings exhibited better glucose tolerance and higher physical activity levels than LCR weanlings. Higher respiratory capacities were observed in the soleus, heart, and liver tissues of HCR weanlings compared with LCR weanlings, which were not owed to greater mitochondrial content. Proteomic analyses indicated a greater potential for lipid oxidation in the contractile muscles of HCR weanlings. In conclusion, offspring born to parents with high CRF possess an enhanced capacity for lipid catabolism and oxidative phosphorylation, thereby influencing metabolic health. These findings highlight that intrinsic CRF shapes the bioenergetic phenotype with implications for metabolic resilience in early life.NEW & NOTEWORTHY Inherited cardiorespiratory fitness (CRF) influences early life bioenergetics and metabolic health. Higher intrinsic CRF was associated with reduced adiposity and improved glucose tolerance in early life. This metabolic phenotype was accompanied by greater mitochondrial respiratory capacity in skeletal muscle, heart, and liver tissue. Proteomic profiling of these three tissues further revealed potential mechanisms linking inherited CRF to early life metabolism.

Influence of Guar Meal from Pig Compound Feed on Productive Performance, Nitrogen Metabolism, and Greenhouse Gas Emissions

Guar (Cyamopsis tetragonoloba) is an annual legume tolerant to drought. Guar meal (GM) is a protein- and carbohydrate-rich co-product generated after the mechanical separation of the endosperm from the germ and hull of guar seed. GM has received considerable interest in animal feed as an alternative to soybean meal (SM). In this study, we aimed to assess the nitrogen (N) balance indicators, performance, carcass traits, and main greenhouse gas (GHG) emissions resulting from enteric fermentation (E-CH4) and manure (M-CH4 and N2O). Two tests were performed: (i) a biological trial on 45 pigs (15 animals/group) and (ii) a digestibility test in metabolism cages (N = 15, 5 replicates/group). Three different diets were given to the pigs: one diet was based on 0% GM (SM diet); in the second, GM-50%, GM replaced 50% of the SM; and the third was GM-100%, in which GM fully replaced the SM. The GM and SM diets were analyzed for their proximate composition. A model based on prediction equations was used to estimate the GHGs. GM up to 10% in the diets of finishing pigs did not significantly impact growth performance or carcass traits, although a slight increase in neutral detergent fiber (NDF) was observed. GM up to 10% improved N digestibility (p &lt; 0.0001), net protein utilization (p &lt; 0.0001), the biological value of protein, coefficients of metabolizability, and the coefficient of the total tract’s apparent digestibility. Irrespective of its dietary proportion, GM decreased total nitrogen output (TNO, p = 0.11). A highly significant impact was noted for N2O and E-CH4 (for DM, p &lt; 0.0001), as well as a significant impact for E-CH4, expressed as g CO2 Eq (p = 0.007), and g CO2 Eq. LU (livestock unit, p = 0.005), also reported as ADG (p = 0.024). Manure, M-CH4, was not significantly influenced. In conclusion, GM can replace up to 100% SM and is thus a valuable byproduct that does not alter animal performance and can positively impact N2O and E-CH4.

Acute over-additive natriuretic effects by a combination of finerenone and SGLT2 inhibition in rats with an activated renin-angiotensin-aldosterone system: a mechanistic basis for clinical outcomes?

Abstract Background Recent preclinical studies suggested an independent benefit of non-steroidal mineralocorticoid receptor (MR) antagonism by finerenone and SGLT2 inhibition in cardiorenal diseases, with a potential for combination therapy. Chronic low-dose combination of finerenone and empagliflozin in hypertensive rats revealed an early, sustained and over-additive reduction in proteinuria but the underlying mechanism(s) are not fully understood. Purpose To compare the acute glucosuric, natriuretic, kaliuretic and diuretic efficacy of individual dosages of finerenone and SGLT2 inhibitors (empagliflozin, canagliflozin or dapagliflozin) with the combined administration of both drug classes in conscious rats with an activated renin-angiotensin-aldosterone system (RAAS). Methods The RAAS was activated in male Wistar rats (body mass 250 to 500 g) by placing them on a low-salt diet containing 0.02% sodium chloride for 72 hours. In a series of three independent experiments, finerenone (1 mg/kg), SGLT2 inhibitor (3 mg/kg; either empagliflozin, canagliflozin or dapagliflozin) alone and the respective combinations were administered in 2-3 ml/kg of solvent (PEG400) by oral gavage and the animals (n=6-10 / group) were individually placed in metabolic cages on water ad libitum. The individual urine was collected for 24 hours and the concentration of glucose, sodium and potassium excreted in the urine was measured by a clinical-chemical analyzer system (ADVIA 2400). Results Administration of 1 mg/kg finerenone had no influence on urinary glucose, urinary volume and urinary potassium but caused an increase in urinary sodium excretion at least by trend. At a dose of 3 mg/kg, all SGLT2 inhibitors induced a strong increase in urinary glucose excretion but had no significant influence on urinary potassium and urinary sodium, while only dapagliflozin caused an increase in urinary volume at the tested dose. Administration of a combination of 1 mg/kg finerenone and 3 mg/kg SGLT2 inhibitor did not significantly modify urinary glucose and urinary potassium in comparison to the respective individual finerenone and SGLT2 inhibitor dosages and only the combination with empagliflozin increased urinary volume vs the respective monotherapies. Surprisingly, combination of finerenone with SGLT2 inhibition over-additively induced sodium excretion consistently in all three experiments (finerenone+empagliflozin: 171,4%; finerenone+canagliflozin: 139,6%; finerenone+dapagliflozin: 133,9%) in comparison to the calculated combination (set to 100%) of the respective individual finerenone and SGLT2 inhibitor groups. Conclusion Combination of MR antagonism by finerenone and SGLT2 inhibition revealed an acute over-additive natriuresis in a rat diuresis model. This might provide an additional mechanistic basis for near-term (e.g. hospitalization for heart failure) and long-term outcomes (e.g. blockade of the progression of kidney failure) in cardiorenal patient populations.

A clinically-relevant mouse model that displays hemorrhage exacerbates tourniquet-induced acute kidney injury.

Hemorrhage is a leading cause of death in trauma. Tourniquets are effective at controlling extremity hemorrhage and have saved lives. However, tourniquets can cause ischemia reperfusion injury of limbs, leading to systemic inflammation and other adverse effects, which results in secondary damage to the kidney, lung, and liver. A clinically relevant animal model is critical to understanding the pathophysiology of this process and developing therapeutic interventions. Despite the importance of animal models, tourniquet-induced lower limb ischemia/reperfusion (TILLIR) models to date lack a hemorrhage component. We sought to develop a new TILLIR model that included hemorrhage and analyze the subsequent impact on kidney, lung and liver injuries. Four groups of mice were examined: group 1) control, group 2) hemorrhage, group 3) tourniquet application, and group 4) hemorrhage and tourniquet application. The hemorrhagic injury consisted of the removal of 15% of blood volume through the submandibular vein. The tourniquet injury consisted of orthodontic rubber bands applied to the inguinal area bilaterally for 80min. Mice were then placed in metabolic cages individually for 22h to collect urine. Hemorrhage alone did not significantly affect transcutaneous glomerular filtration rate (tGFR), blood urea nitrogen (BUN) or urinary kidney injury molecule-1 (KIM-1) levels. Without hemorrhage, TILLIR decreased tGFR by 46%, increased BUN by 162%, and increased KIM-1 by 27% (p < 0.05 for all). With hemorrhage, TILLIR decreased the tGFR by 72%, increased BUN by 395%, and increased urinary KIM-1 by 37% (p < 0.05 for all). These differences were statistically significant (p < 0.05). While hemorrhage had no significant effect on TILLIR-induced renal tubular degeneration and necrosis, it significantly increased TILLIR-induced lung total injury scores and congestion, and fatty liver. In conclusion, hemorrhage exacerbates TILLIR-induced acute kidney injury and structural damage in the lung and liver.

Abstract 15250: Increased CD81 is Associated With Enhanced Apoptosis in Acute Kidney Injuries Induced by Candesartan/Low Salt Diet

Introduction: Our previous studies have demonstrated that the upregulation of renal CD81 (cluster of differentiation 81), contributes to the sustained hypertension observed in LPS-preeclampsia rats with kidney injuries. Candesartan (Can) lowers blood pressure by selectively blocking type 1 angiotensin II receptors and results in acute kidney injury (AKI) when used together with dietary sodium restriction. Various cell deaths including apoptosis and necrosis are involved in the pathogenesis of AKI. Hypothesis: Renal CD81 may increased in candesartan/low salt diet(LS+Can) model via activation of apoptosis. Methods: Male SD rats aged 8-10 weeks were fed with LS (0.01% NaCl) or normal salt diets (NS, 0.8% NaCl) (6-10rats/group) respectively for 7 days.All rats were intraperitoneally injected with candesartan (1mg/kg/d) simultaneously.Systolic blood pressure(SBP) was monitored with tail-cuff method.The rats were sacrificed by over-anesthesia after the samples of blood and urine (metabolic cage) were collected.The kidneys were immediately removed for immunoblotting, and TUNEL(TdT-mediated dUTP Nick-End Labeling) measurements.P&lt;0.05 was considered significant for 2 group comparison with t-test. Results: Compared with rats on NS+Can, the serum creatinine (20.3±0.3 vs 50.8±4.2 mmol/L) and BUN(4.05±0.2 vs 18.6±2.5 mmol/L) were more than doubled in LS+Can rats ;Creatinine clearance was decreased (100±4.1 vs 40.8±3.7ml/min); systolic blood pressures was lowered slightly (101.7±1.7 vs 88.9±2.7mmHg, n=7-8). Renal CD81 protein abundance by immunoblotting was increased (258.8±52.4,% of control, n=6/group,p&lt;0.05, same as below).At the same time, there were increases in apoptosis-associated proteins including bax(312.6±71.5),caspase-3(124.6±6) ,cleaved caspase3(133.8±9.6) in Can+LS group.The rate of tunel-positive cells was elevated in the Can+LS group. (100.0±8.5 vs 482.72±59.4,p&lt;0.05,n=10/group).However, necrosis-related inflammatory factors, including Interleukin-6,tumor necrosis factor-α, were not affected in the rat kidneys from LS+Can treated rats. Conclusions: Our findings suggest that Increased CD81 may be associated with enhanced apoptosis in rat kidneys with acute kidney injuries.

349 Effects of Adding a Yeast Blend to Diets with High Levels of Dried Distillers Grains on Feeding Behavior, Intake, and Performance of Beef Cattle Fattened in Feedlot

Abstract Feeding ruminants with a blend of autolyzed yeast grown on sugarcane molasses and live yeast allows nutritionists to explore synergistic effects on digestion and performance (Angulo et al.,2021; Zapata et al., 2021). However, the feeding behavior and the challenges faced in large pen feedlot operations differ from the behavior and challenges faced by animals studied in small groups or metabolic cages. Therefore, we aimed to study the feeding behavior and performance of beef cattle fed in groups in large pens, mimicking the feedlot operations of leading producers and exports of meat in the world. The trial lasted 112 days and was conducted in Nutripura’s research center in the midwest of Brazil. Six hundred five non-castrated males (Nelore and F1 Nelore-Angus), 405 kg (± 35), distributed in 20 pens, were divided into two treatments: 1) Control, a diet with no yeast additives; 2) Yeast Blend (YB), a diet with a blend of autolyzed yeast and live yeast, SymbioYeast, 7g/anima/day (ICC, São Paulo, Brazil). Both diets contained monesin (28 mg/kg DM). The data were analyzed in the software SAS following the model Yijk= μ+Ti + Fj + Bk +еijk (μ = general mean; T = treatment effect; F = Breed effect; B = backgrounding phase effect; e = error). Initial body weight was used as a covariable to analyze final body weight and average daily gain (ADG). Dry matter intake increased (P &amp;lt; 0,05) when animals were supplemented with YB (10,99kg vs. 11,12kg). Final body weight and hot carcass weight tended (0.1 &amp;gt; P ≥ 0.05) to increase when YB was added to the diet. (598 kg vs. 602 kg, 343 kg vs. 345 kg). The ADG was unaffected (P = 0.1069, control 1.735 kg, and YB 1.768 kg). Increasing DMI is a well now property of some yeast derivatives (Torres et al., 2022). This may be related to changes in digestion (Torres et al., 2022) and the diet’s palatability. The palatability of yeast products is claimed on organoleptic and flavor characteristics (Tao et al., 2023). Drone photos taken every 15 minutes suggested that YB altered how animals interact with feed. Feed was delivered between 0700 h and -0930 h and 1300 h and 1530 h. After delivery, a greater percentage of the visit of the animals to the feed bunkers in YB groups. This behavior was even more evident in the morning feed delivery (Figure 1). In summary, YB increased intake and performance. It also changed the interest of animals in visiting feed bunk.

PSIV-27 Effect of Different Ratios of Phytogenic Feed Additives in Weaned Pigs Challenged with a Pathogenic Escherichia Coli

Abstract This study was conducted to investigate the effects of supplementing different ratios of phytogenic feed additive (PFA) to weaned pigs challenged with pathogenic Escherichia coli (E. coli) on growth performance, nutrient digestibility, intestinal barrier integrity, and immune response, and to determine the optimal mixing ratio for PWD prevention. A total of 48 four-week-old weaned pigs with initial body weight of 8.01 ± 0.39 kg were placed in individual metabolic cages, and then randomly assigned to eight treatment groups. The eight treatments were as follows: a basal diet without E. coli challenge (negative control, NC), a basal diet with E. coli challenge (positive control, PC), PC with supplementing 0.1% mixture of 20 % bitter citrus extract (BCE), 10% microencapsulated blend of thymol and carvacrol (MEO), and 70% excipient (T1), PC with supplementing 0.1% mixture of 10% MEO, 20% premixture of grape seed and grape marc extract, green tea, and hops (PGE), and 60% excipient (T2), PC with supplementing 0.1% mixture of 10% BCE, 10% MEO, 10% PGE, and 70% excipient (T3), PC with supplementing 0.1% mixture of 20% BCE, 20% MEO, and 60% excipient (T4), PC with supplementing 0.1 % mixture of 20% MEO, 20% PGE, and 60% excipient (T5), and PC with supplementing 0.1 % mixture of 10% BCE, 20% MEO, 10% PGE, and 60% excipient (T6; Table 1). The experiments were progressed in 16 days, including 5 days before and 11 days after the first E. coli challenge (d 0). In the E. coli challenge treatments, all pigs were orally inoculated by dividing a total of 10 mL of E. coli F 18 for 3 consecutive days from d 0 post-inoculation (PI). Compared with the PC group, the PFA2 and PFA6 groups significantly increased (P &amp;lt; 0.05) feed efficiency and decreased (P &amp;lt; 0.05; Table 2) diarrhea during the entire period (Table 3). At d 11 PI, the PFA6 group significantly improved (P &amp;lt; 0.05) gross energy digestibility compared with the PFA1 group (Table 4). The PFA6 group significantly decreased (P &amp;lt; 0.05) tumor necrosis factor α (TNF-α) and interleukin-6 (IL-6) in serum (Table 5) and increased (P &amp;lt; 0.05) the villus height to crypt depth ratio (VH:CD; Table 6; Figure 1). The PFA2 significantly decreased (P &amp;lt; 0.05) the relative protein expression of calprotectin in the ileum (Table 7). In conclusion, improvements in growth performance, diarrhea reduction, and immunity enhancement are demonstrated when 10% BCE, 20% MEO, 10% PGE, and 60% excipient are mixed.

Study of Sequence of Histopathological Changes in Hyperglycaemia-Induced Experimental Diabetic Nephropathy in Wistar Rat Model

The sequence of histopathological changes in hyperglycaemia-induced nephrotoxicity as well as alteration in renal parameters is still not well established in diabetic models. Hyperglycaemic ambience has been shown to generate oxidative stress which becomes a trigger for further degenerative changes that occur in the microenvironment of the kidney. This study was therefore intended to investigate histopathological alterations in vascular, glomerular and tubulointerstitial compartments of the renal tissues, and the corresponding changes in values of oxidative stress markers, creatinine clearance, proteinuria and serum creatinine concentration in a duration of three, seven and twelve weeks of sustained hyperglycaemia in diabetic. The experiment included four groups of adult Wistar rat, Group A (Normal Control, treated with normal saline), Groups B, C and D were induced with diabetes (treated with 65mg/kg body weight of streptozotocin) and allowed for 3 weeks 7 weeks and 12 weeks respectively. At termination, Oxidative stress markers were analyzed using Oxidative stress marker kits. A 24 hours urine collection was obtained from metabolic cages few hours before sacrifice and used for renal analysis and histopathological examination was done using a light microscope. Results reveals that oxidative stress was climaxed at 7th week and was maintained at a constant level while histopathological changes in glomerulus first presented on the 3rd week accompanied by vascular changes. Tubulointerstitial changes were noticed on the 7th week. On the 12th week renal parameters were significantly altered when compared to the animals sacrificed on 3th and 7th week. In conclusion, the sequence in diabetic–induced renal dysfunction begins with changes in vascular and glomerular compartment followed by distortion in tubulointerstitial compartment. An alteration in renal parameters presents lastly and correlates with the histopathological changes. These findings can be adopted in clinical management and treatment of diabetes-induced kidney dysfunction. J. Bio-Sci. 31(1): 29-37, 2023

Effect of black soldier fly larvae as substitutes for fishmeal in broiler diet.

This study investigated the effect of processed forms (defatted or hydrolyzed) of black soldier fly larvae (Hermetia illucens L., BSFL) as a protein substitute on broilers. Experiment 1 was a feeding experiment, and Experiment 2 was a metabolism experiment. In Experiment 1, a total of 120 day-old Arbor Acres broilers (initial body weight 39.52 ± 0.24 g) were used for 28 days. There were 8 replicate pens, and 5 broilers were assigned to each pen. In Experiment 2, a total of 36 day-old broilers (initial body weight 39.49 ± 0.21 g) were used for the metabolism trial. There were 2 broilers in a metabolism cage and six replicate cages per treatment. The dietary treatments were as follows: a basal diet (CON), a basal diet without fishmeal and substitute with defatted BSFL (T1), a basal diet without fishmeal and a substitute with hydrolyzed BSFL (T2). In Experiment 1, during the entire experimental period, the T2 group significantly increased (p < 0.05) body weight gain and feed intake compared to the CON and T1 groups. The feed conversion ratio showed a lower tendency (p = 0.057) in the T2 group than in the CON and T1 groups. At 2 weeks, the CON and T2 groups were significantly higher (p < 0.05) crude protein (CP) digestibility than the T1 group. At 4 weeks, the total protein level significantly increased (p < 0.05) in the CON and T2 groups compared to the T1 group. In Experiment 2, the CP digestibility significantly increased (p < 0.05) in the T2 group compared to the CON and T1 group at weeks 2 and 4. At week 4 amino acid digestibility, the T2 group significantly increased (p < 0.05) lysine, methionine, tryptophan, and glycine digestibility compared to the T1 group. There was no difference in fecal microbiota among the treatment groups. In conclusion, feeding hydrolyzed BSFL as a fishmeal substitute in broiler diets improved growth performance, CP digestibility, and specific amino acid digestibility. Therefore, it is considered that hydrolyzed BSFL in broiler diets can be sufficiently used as a new protein source.

The Assessment of the Efficacy of Imperatorin in Reducing Overactive Bladder Symptoms

Overactive bladder syndrome (OAB) is a prevalent condition that affects the elderly population in particular and significantly impairs quality of life. Imperatorin, a naturally occurring furocoumarin, possesses diverse pharmacological properties that warrant consideration for drug development. The aim of this study was to investigate the potential of imperatorin (IMP) to attenuate the cystometric and biochemical changes typically associated with retinyl acetate-induced overactive bladder (OAB) and to assess its viability as a pharmacological intervention for OAB patients. A total of 60 rats were divided into four groups: I—control, II—rats with rapamycin (RA)-induced OAB, III—rats administered IMP at a dose of 10 mg/kg/day, and IV—rats with RA-induced OAB treated with IMP. IMP or vehicle were injected intraperitoneally for 14 days. The cystometry and assessment of bladder blood flow were performed two days after the last dose of IMP. The rats were then placed in metabolic cages for 24 h. Urothelial thickness measurements and biochemical analyses were performed. Intravesical infusion of RA induced OAB. Notably, intraperitoneal administration of imperatorin had no discernible effect on urinary bladder function and micturition cycles in normal rats. IMP attenuated the severity of RA-induced OAB. RA induced increases in urothelial ATP, calcitonin gene-related peptide (CGRP), organic cation transporter 3 (OCT3), and vesicular acetylcholine transporter (VAChT), as well as significant c-Fos expression in all micturition areas analyzed, which were attenuated by IMP. Furthermore, elevated levels of Rho kinase (ROCK1) and VAChT were observed in the detrusor, which were reversed by IMP in the context of RA-induced OAB in the urothelium, detrusor muscle, and urine. Imperatorin has a mitigating effect on detrusor overactivity. The mechanisms of action of IMP in the bladder appear to be diverse and complex. These findings suggest that IMP may provide protection against RA-induced OAB and could potentially develop into an innovative therapeutic strategy for the treatment of OAB.

Nitrogen Utilization in Goats Consuming Buffelgrass Hay and Molasses-Based Blocks with Incremental Urea Levels.

The use of goats for meat production faces challenges from environmental and nutritional factors. Urea is an affordable non-protein nitrogen source commonly utilized in ruminant nutrition. The objective of this study was to investigate nitrogen utilization in goats fed low-quality hay supplemented with molasses blocks containing urea. Twenty Anglo-Nubian doelings were individually housed in metabolic cages and provided with chopped Buffelgrass (Cenchrus ciliaris) hay ad libitum. Goats were randomly assigned to four urea levels (0, 2, 4, and 6%; n = 5 per treatment) in molasses blocks for a duration of 30 days. A negative nitrogen balance (-2.458 g/day) was observed in doelings consuming blocks without urea, compared with a positive balance (0.895 g/d) for those consuming the 6% urea blocks. Block nitrogen intake significantly increased with urea level, but urea supplementation did not affect dry matter (DM) or neutral detergent fiber (NDFom) intake or digestibility. A minimum crude protein (CP) requirement of 8% for maintenance in doelings consuming low-quality forage with a urea-based supplement was determined through regression analysis between CP intake (% of DM) and N balance (r2 = 0.479; p < 0.002). The value of 8% of CP obtained in this study is similar to several previous studies reported in the literature, but in this case, the increments in CP came exclusively from urea. In this study, increasing the urea content of molasses blocks up to 6% significantly increased nitrogen intake, retention, and balance in goats. These results contribute to a better understanding of nitrogen utilization in goats fed low-quality hay with urea supplementation.

Excitatory purinergic and cholinergic expression changed in a partial bladder outlet obstruction-induced overactive bladder rat model

Overactive bladder (OAB) is a common, long-term symptom complex with a high prevalence in women worldwide. OAB has caused a social burden, and effective treatments are urgently needed. However, the pathogenesis of OAB has yet to be elucidated. Model rats underwent bladder outlet obstruction surgery. In the 2nd, 3rd, and 4th weeks after surgery, metabolic cages were used to detect the 12 h urine volume of rats in the sham and model groups. The urodynamic parameters bladder leak point pressure (BPLL), maximum voiding pressure (MVP), residual volume (RV), maximum bladder capacity (MBC), bladder compliance (BC), voided efficiency (VE), and non-voiding contractions (NVCs) were also detected. Moreover, the contractile responses of isolated detrusor muscles to electrical and carbachol stimulation were examined at the abovementioned time points. At the 4th week after surgery, the bladders of both groups were obtained for hematoxylin–eosin (H&E) and Masson’s trichrome staining. Real-time qPCR and Western blot were performed to quantify the expression of choline acetyltransferase (ChAT) and solute carrier family 17 member 9 (SLC17A9). At week 4, compared with the sham group, the 12 h urine volume of PBOO group increased significantly. The BLPP, MVP, VE, MBC, and NVCs increased significantly, and the VE was significantly reduced in 4-week PBOO group. The contractile responses of isolated detrusor muscles to electrical and carbachol stimulation significantly increased in 4-week PBOO group. In the 4-week PBOO group, the bladder wall and the ratio of bladder muscle to collagen within the bladder smooth muscle layer wall were significantly higher than those in the sham group. ChAT and SLC17A9 mRNA and protein expression in the OAB model rats significantly increased. At 4 weeks after PBOO, the OAB model was successfully established. The gene and protein expression levels of ChAT and SLC17A9 increased in the bladder of the OAB model, suggesting that OAB may be related to increased excitatory purinergic and cholinergic expression.

METTL3 inhibitor STM2457 improves metabolic dysfunction-associated fatty liver disease by regulating mitochondrial function in mice

To investigate the effect of methyltransferase-like 3 (METTL3) inhibitor STM2457 in metabolic dysfunction-associated fatty liver disease (MAFLD). C57BL/6J mouse models of MAFLD induced by high-fat diet feeding for 16 weeks were treated with intraperitoneal injections of STM2457 (50 mg/kg) for 2 weeks. The changes in m6A modification level in the liver tissue of the mice were determined with dot-blot hybridization, and the hepatic levels of triglyceride (TG), alanine aminotransferase (ALT) and glutathione aminotransferase (AST) were detected. The histological changes of the liver and changes in insulin resistance and metabolic profile of the mice were evaluated using HE staining, insulin tolerance tests and metabolic cages; transmission electron microscopy (TEM) was employed to examine the changes in mitochondrial morphology. In a HepG2 cell model of steatosis induced by treatment with sodium oleate/sodium palmitate for 48 h, the protective effect of STM2457 (1 μmol/L) on mitochondrial function was assessed by measuring mitochondrial membrane potential using a fluorescence probe (JC-1). The mouse models of MAFLD showed significant elevation of m6A modification level in the liver tissues and obviously upregulated mRNA expression of METT3 (P<0.05). Treatment with STM2457 significantly reduced body weight and liver lipid deposition and m6A modification levels, increased glucose tolerance and insulin sensitivity, lowered hepatic TG and serum ALT and AST levels, and increased respiratory entropy (RQ) in the mouse models (all P<0.05). HepG2 cells with steatosis exhibited obvious mitochondrial swelling with decreased mitochondrial membrane potential, but the STM2457-treated cells maintained a normal mitochondrial morphology with a higher membrane potential (P<0.05). The METTL3 inhibitor STM2457 improves MAFLD by reducing high-fat diet-induced mitochondrial damage in mice.

OR10-02 Effect Of Phosphodiesterase 4 Inhibitors On Weight Loss And Energy Homeostasis In Mice With Obesity Induced By A High-fat-diet

Abstract Disclosure: M.A. de Andrade: None. H. da Silva: None. A.A. Jesus: None. F.J. de Paula: None. L. Elias: None. INTRODUCTION: Obesity is a worldwide health problem and the incidence of associated diseases such as type 2 diabetes is increasing. Leptin (Lep) resistance arises from obesity-related inflammation, enhancing the appetite. The expression of phosphodiesterase 4 enzymes (PDE4) is increased in inflammatory conditions. Rolipram (Rol) acts to inhibit PDE4 reducing adiposity and peripheral inflammation. Notwithstanding, the effects of Rol on Lep sensitivity and energy balance are still unknown. Objective: To evaluate the effect of PDE4 inhibition on energy homeostasis and Lep sensitivity and glucose tolerance in mice with obesity induced by a high-fat diet (HFD). Methodology: Four-week-old male C57BL6 mice were fed a HFD (60%, Research Diets) or chow diet (C) for 10 weeks. In the 8th week, they received daily subcutaneous Rol injections (2mg/kg) or vehicle (V) and food intake and body weight were daily measured. Energy expenditure (EE) was measured on the 8th day of treatment using a metabolic cage (Oxymax). After treatment, mice underwent 6h fasting and subsequent intraperitoneal (i.p.) glucose injection (2g/kg). Fasting blood glucose (FG) and 120 minutes after glucose (GTT) were measured. On the last day of treatment, 90 minutes after the Rol or V injection, i.p. Lep (5mg/kg in 100ul) or saline (S) was injected, and weight and food intake were measured 14 and 24h later. Results: 5-10 mice were analyzed in each group (chow + V, CV; chow + Rol, CR; HFD + V, HV; HFD + Rol, HR). There was a significant difference in body weight between HR and HV: absolute weight (HR 35+-4.18; HV 38.8+-3.88g; p 0.038) and weight variation (HR -2.26+-0.99; HV -0.19+-1.25g; p 0.002), but no difference between CR and CV (27.98+-2.25; 26.8 +- 2.22g, p 0.97). Rol effectively reduced ingestion in both diets (CR 42.85+-2.7; CV 48.13+-4.51g; p 0.03) (HR 24.75+-2.44; HV 28.31 +-2.81g; p 0.01). In the HFD groups, compared to V, Rol increased VO2 (p 0.04) and energy expenditure (p 0.049) as well as the heat (p 0.03). There was no difference in VCO2 nor motor activity. Lep sensitivity was evaluated in the HFD group and there was a significant reduction in food intake 24h after the Lep application compared to S (Lep 2.18+-0.2; S 2.47+-0.18g, p 0.04). There was no difference in food intake 14h after Lep or weight after injection at either time point (14/24h). Rol was ineffective to improve FG/GTT in the HFD group. Conclusion: Rolipram, a PDE4 inhibitor, effectively reduces the body weight of diet-induced obesity by reducing food intake, increasing basal energy expenditure and improving leptin sensitivity. PDE4 appears as a potential target to treat obesity. Presentation: Friday, June 16, 2023

SAT002 Liver-specific Loss Of The Nuclear Receptor Co-regulator ARGLU1 Protects Against Diet-induced Obesity In Female Mice Independent Of Food Intake And Energy Expenditure

Abstract Disclosure: S.B. Cash: None. L. Magomedova: None. R. Tsai: None. C.L. Cummins: None. Arginine and glutamate rich 1 (ARGLU1) has been shown to be a co-regulator for several nuclear receptors including ER, GR and the peroxisome proliferator-activated receptors (PPARs), which are key modulators of nutrient metabolism. We have previously reported that loss of ARGLU1 in the liver protects aged male mice against high-fat diet induced obesity and type 2 diabetes [1]. Here, we assessed the importance of ARGLU1 in lipid and carbohydrate metabolism in aged female mice and used indirect calorimetry to understand the metabolic basis of the resistance to weight gain observed with liver-specific loss of ARGLU1. Aged (11-month-old) female wildtype floxed-Arglu1 mice (Arglu1fl/fl) and liver-specific Arglu1-null mice (Arglu1LKO) were fed a high fat, high cholesterol diet (HFD, 42% calories from fat, TD.88137 Envigo) for 12-weeks (N=7-17). Female mice were housed in Promethion Metabolic Cages (Sable Systems) at room temperature for 5 days during which their food intake, water intake, physical activity, O2 consumption, and CO2 production were measured (N=5-7). Female mice were also subjected to a glucose tolerance test and insulin tolerance test (N=4-8). In agreement with our previous results in male Arglu1LKO mice [1], female Arglu1LKO mice were resistant to diet-induced obesity with final body weights compared to HFD-fed Arglu1fl/fl mice of 30.6 ± 0.9 g vs 35 ± 1 g (P&amp;lt;0.05). Likewise, female Arglu1LKO mice were more glucose tolerant and insulin tolerant compared to HFD-fed Arglu1fl/fl mice. The metabolic cage data showed no change in food intake, locomotor activity or energy expenditure between HFD-fed Arglu1fl/fl and Arglu1LKO mice when accounting for body mass as a covariate (ANCOVA, CalR). Surprisingly, HFD-fed female Arglu1LKO mice had significantly higher water intake compared to HFD-fed Arglu1fl/fl mice (P&amp;lt;0.02). These data support the conclusion that resistance to diet-induced obesity in Arglu1LKO mice is independent of sex. To our surprise, based on the metabolic cage data, we conclude that the mechanism by which Arglu1LKO mice are resistant to diet induced obesity is not due to enhanced energy expenditure or decreased food intake. Future studies will explore whether differential intestinal lipid absorption (independent of food intake) could account for the differences we observed in weight gain between the genotypes. [1] Magomedova, L., Tsai, R., &amp; Cummins, C. L. (2017, April). Hepatic Ablation of the Nuclear Receptor Coactivator, ARGLU1, Is Protective Against the Development of Type 2 Diabetes and Fatty Liver in High-Fat Diet Fed Mice. In 99th Annual Meeting of the Endocrine Society. Endocrine Society. Presentation: Saturday, June 17, 2023

SIRT1 induction in the skeletal muscle of male mice partially attenuates changes to whole-body metabolism in response to androgen deprivation

In males, androgens regulate whole body metabolism. The components in androgen target organs contributing to whole-body metabolic function remain ill defined. Sirtuin1 (SIRT1) protein levels are lower in the limb muscle of male mice subjected to androgen deprivation. Because SIRT1 can influence whole-body metabolism, the purpose was to assess whether muscle specific SIRT1 induction attenuated changes to whole-body metabolism in response to androgen deprivation. Physically mature male mice containing an inducible muscle specific SIRT1 transgene (SIRT1) were subjected to a sham or castration surgery and compared to sham and castrated male mice where the SIRT1 transgene was not induced (WT). The respiratory exchange ratio (RER), energy expenditure, and carbohydrate and fat oxidation rates were determined using metabolic cages. Castration lowered RER in WT mice and the lower RER coincided with lower energy expenditure, lower carbohydrate oxidation rates, and higher fat oxidation rates. SIRT1 induction attenuated the castration-induced changes to RER and fat oxidation rates. Changes to energy expenditure and glucose oxidation rates were not affected by SIRT1. Decreases in muscle SIRT1 protein in males may partially contribute to the dysregulation of whole-body metabolism in response to androgen deprivation.