Cumulative Food Intake Research Articles

OR04-03 Calcitonin Receptor Expressing Neurons in the PVH Regulate Feeding Behavior

The paraventricular nucleus of the hypothalamus (PVH) is a brain region crucial for energy homeostasis. Abnormal PVH development or damage leads to hyperphagic obesity and energy expenditure deficits underscoring the importance of PVH neuronal activity in energy balance control. Application of salmon calcitonin (sCT) to the PVH suppresses feeding and calcitonin receptor (CalcR) is highly expressed in the PVH of rodents suggesting that CalcR-expressing PVH neurons contribute to energy homeostasis. In situ hybridization reveals that many CalcRPVH neurons express melanocortin-4 receptor (MC4R), a receptor required for normal feeding behavior. To investigate the physiologic roles of CalcRPVH neurons, we generated CalcR-2a-Cre knock-in mice to manipulate CalcR-expressing cells. Deletion of MC4R from CalcR expressing cells using Cre-loxP technology resulted in profound obesity in both male and female mice by 16 weeks of age. This weight gain was attributable to hyperphagia, as cumulative food intake of the MC4R deleted mice was significantly greater than the controls and energy expenditure measurements acquired through CLAMS analysis were not significantly different. To determine the brain regions engaged by CalcRPVH neurons, we used anterograde Cre-dependent viral tracing reagents injected into the PVH of CalcR-Cre mice, and found that CalcRPVH neurons project to brain regions implicated in energy balance control, including the nucleus of the solitary tract and the parabrachial nucleus. To assess the acute effects of activating CalcRPVH neurons, we used DREADD technology to chemogenetically activate CalcRPVH neurons. CalcRPVH neuron activation suppressed feeding but had no significant effect on energy expenditure. To determine if the activity of CalcRPVH neurons is required for energy homeostasis, we silenced them using Cre-dependent tetanus toxin virus. Male mice with tetanus toxin silenced CalcRPVH neurons were obese 7 weeks following injection in part due to greater cumulative food intake; CLAMS analysis revealed no differences in energy expenditure. Mice with silenced CalcRPVH neurons as well as mice with CalcR deleted from the PVH had normal anorectic responses to sCT, suggesting sCT-induced anorexia does not require CalcRPVH neurons or CalcR expression in the PVH. Taken together, these findings suggest CalcRPVH neurons are an essential component of feeding and energy homeostatic circuitry.

SUN-644 Effects of Steroid Hormones on Lipogenesis and Insulin Sensitivity - an Insight into the Involvement of the Wnt Signaling Pathway

Gestational diabetes mellitus (GDM), a condition in which the state of pregnancy induces the development of diabetes, is characterized by heightened maternal insulin resistance. The levels of sex steroid hormones generally increase during pregnancy. It is thought that imbalance in the levels of steroids like estradiol (E2) and progesterone (P4) with respect to each other, may increase susceptibility towards GDM. To understand the metabolic effects of these steroids, ovariectomized (OVX) rats were treated with E2 or P4 at dosages mimicking the true hormonal status as in pregnancy. E2 significantly reduced the body weight gain (145.4±1.4% to 108.3±0.8%, p<0.001, n≥12) as well as the cumulative food intake (391.3±14.6 g to 312.5±9.0 g, p<0.001) over the course of the 23 day-treatment period. It also decreased the quantity of accumulated gonadal white adipose tissue (GWAT) in the body (3.3±0.2 g to 1.1±0.1 g, p<0.001) and repressed expression of lpl (1.3±0.2 fold, p<0.05) and other lipogenesis markers. P4, on the other hand, enhanced lpl expression (3.7±0.2 fold, p<0.001), but did not affect the total quantity of GWAT. Further, E2 treatment brought about an increase in the expression of insulin sensitivity markers like insr in the GWAT (4.5±0.6 fold, p<0.001) and soleus skeletal muscle (6.2±0.3 fold, p<0.001), as well as an increase in the protein levels of GLUT4.GDM susceptibility in pregnant women is most commonly associated with SNPs in the tcf7l2 gene, the product of which is an effector of the canonical Wnt signaling pathway. It has also been reported that certain actions of steroid hormones are mediated by Wnt signaling. Moreover, we found that tcf7l2 and other components of this pathway (β-catenin protein, lrp5) were up-regulated following treatments with E2 (3.8±0.2 fold, p<0.001 in GWAT; 5.3±0.2 fold, p<0.001 in soleus) and P4 (2.1±0.2 fold, p<0.05 in GWAT; 2.9±0.3 fold, p<0.001 in soleus). We therefore hypothesized that the metabolic actions of these steroids may be mediated by Wnt signaling. To test this hypothesis, we conducted experiments in which OVX rats treated with steroids as described above, were additionally treated with niclosamide (NIC), a Wnt pathway inhibitor. NIC in conjunction with E2 increased GWAT accumulation and lipogenesis, thereby reversing the action of E2. NIC treatment in OVX rats did not change these parameters, indicating that this effect is specific to the inhibition of Wnt signaling modulated by E2. Additionally, NIC inhibited the E2-modulated increase in insulin sensitivity in GWAT and soleus. Taken together, the results suggest that the actions of E2 on insulin sensitivity and lipogenesis are mediated by the Wnt signaling pathway. No such observation was made with respect to the effect of P4 on lipogenesis. Understanding the mechanistic actions of these steroids may play an important role in devising methods to prevent conditions like GDM before its onset.

Effects of cultured dairy and nondairy products added to breakfast cereals on blood glucose control, satiation, satiety, and short-term food intake in young women.

Breakfast cereals are often consumed with dairy products or nondairy alternatives; however, the effect of the combination on blood glucose and food intake control is not well investigated. In a randomized, crossover study, 24 healthy women (age: 22.7 ± 2.5 years; body mass index: 22.1 ± 1.5 kg/m2) consumed, to satiation, 1 of 3 treatments: Greek yogurt with granola (150 kcal, 9.2 g protein, 2.6 g fat, 2.0 g dietary fibre, and 21.5 g available carbohydrate/100 g); cultured coconut product with granola (146 kcal, 3.2 g protein, 3.2 g fat, 5.6 g dietary fibre, and 21.9 g available carbohydrate/100 g); or water control. The data were analyzed with repeated-measures ANOVA. The 2 h blood glucose iAUC was 52% lower after the dairy compared with nondairy treatment (P < 0.0001). While there were no differences in food intake between the caloric treatments consumed to satiation, protein intake was 3 times higher and fibre intake was 4 times lower after the dairy compared with nondairy treatment. Both caloric treatments resulted in similar suppression of ad libitum food intake at 2 h (P < 0.003) and subjective appetite over 2 h (P < 0.0001) compared with water. The cumulative food intake over 2 h was lower after water (P < 0.05). The 1.8-fold increase in postprandial insulin after dairy compared with nondairy treatment may explain the reduction in blood glucose without an increase in subsequent energy intake. Novelty Blood glucose in young females is lower after a breakfast with granola in a high-protein cultured dairy than when in a high-fibre nondairy cultured product. Subjective appetite over 2 h and food intake 2 h later was similarly lower after both breakfasts but cumulative intake was higher compared with breakfast skipping.

Expression of hypothalamic feeding-related peptide genes and neuroendocrine responses in an experimental allergic encephalomyelitis rat model

Experimental allergic encephalomyelitis (EAE) is considered to be a useful animal model of human multiple sclerosis (MS). However, among the various symptoms of MS, the mechanisms contributing to inflammatory anorexia remain unclear. In the present study, we used an EAE rat model to examine changes in expression levels of hypothalamic feeding-related peptide genes and neuroendocrine responses such as the hypothalamo-neurohypophysial system and the hypothalamo-pituitary-adrenal (HPA) axis. The weight gain and cumulative food intake in EAE rats in the early days after immunization was significantly lower than that of the control group. The expression of orexigenic peptide genes Npy and Agrp were significantly increased, whereas the levels of anorectic peptide genes (Pomc and Cart) were significantly decreased in the hypothalamus of EAE rats. There was also a significant increase in the mRNA and plasma oxytocin (OXT) but not of arginine vasopressin (AVP) in the supraoptic and paraventricular nuclei (PVN) of EAE rats at days 12 and 18 after immunization. The expression of corticotropin-releasing hormone (Crh) and Avp was downregulated and upregulated, respectively, in the parvocellular division of the PVN at day 12 after immunization. The expression level of Pomc in the anterior pituitary significantly increased, accompanied by increased plasma corticosterone levels, at days 6, 12, and 18 after immunization. These results suggest that inflammatory anorexia in rat EAE may be caused by activation of the OXT-ergic pathway and HPA axis via changes in the expression of hypothalamic feeding-related peptides, including Avp but not Crh.

Vagal afferent nerve ghrelin signaling influences energy balance and episodic memory

Vagal afferent nerve (VAN) signaling sends sensory information from the gut to the brain and participates in the regulation of meal size and blood glucose control. Recent findings reveal that VAN signaling also plays a critical role in cognitive processes, including hippocampus(HPC)‐ dependent memory function. The nodose ganglia (VAN neurons) express receptors for various gut‐derived endocrine signals, however, the function of these receptors with regards to feeding behavior, glucose regulation, and HPC‐dependent memory is poorly understood. We hypothesized that these VAN‐mediated behavioral and physiological processes are influenced by ghrelin, a stomach‐derived orexigenic hormone, via communication to its receptor (growth hormone secretagogue receptor [GHSR]) expressed on gut‐innervating VAN terminals. To examine this hypothesis, adult male rats received bilateral nodose ganglion injections of an adeno‐associated virus (AAV) expressing short hairpin RNAs targeting GHSR (or a scrambled control AAV) for RNA interference‐mediated VAN GHSR knockdown. Meal‐pattern analyses revealed a significant increase in meal frequency in the VAN GHSR knockdown group compared with controls, coupled with a nonsignificant trend in reduced average meal size such that cumulative 24h food intake did not differ between groups. Results from an intraperitoneal glucose tolerance test revealed impaired glucose tolerance in VAN GHSR knockdown animals vs. controls. Despite no differences in cumulative 24h food intake, the VAN GHSR knockdown group also had significantly increased body weight gain compared with controls. Lastly, to examine the role of VAN GHSR signaling in HPC‐dependent memory function, the rats were tested in novel object in context task that measures contextual episodic memory. Results reveal that VAN GHSR knockdown impairs memory performance in this task, yet has no effect on measures of anxiety‐like behavior or levels of general activity. Collectively, these results reveal that VAN GHSR signaling is important for the control of both energy balance as well as HPCdependent memory function.

The Impact of SGLT‐2 Inhibition on Obesity and the Metabolic Profile in a PCOS Rat Model

Polycystic Ovary Syndrome (PCOS), the most common endocrine disorder in young women, is characterized by hyperandrogenemia, and is associated with obesity and insulin resistance. It is suggested that hyperandrogenemia is the cause of these metabolic complications. Current treatment for obesity in PCOS is lackluster, which is why new therapies are being investigated. Sodium‐glucose co‐transporter‐2 (SGLT‐2) inhibitors such as Empagliflozin (EMPA) have been shown in diabetics to reduce body fat and insulin resistance. We have previously reported that exposure of female rats to dihydrotestosterone (DHT) before puberty resembles many characteristics found in PCOS: increase in food intake (FI), body weight (BW), fat/lean mass, blood pressure, and renal injury. We want to test the hypothesis that EMPA improves obesity and metabolic complications in a PCOS‐like rat model.MethodsForty four‐week old female SD rats were randomized to either placebo (PBO) or DHT exposure (7.5mg/90 days). Body weight was measured weekly. Body composition was analyzed monthly by EchoMRI. Fasting plasma was analyzed monthly for glucose and insulin. A 24‐hour urine was collected in metabolic cages monthly to assess the concentration of urinary glucose. After 10 wks of DHT, rats were randomized to receive drinking water alone or with EMPA (10mg/kg/day) for another 3 wks. FI was measured daily. At the end of the treatment, body composition, fasting plasma, and glucosuria were assessed. Morning plasma was collected for leptin and adiponectin after 3 wks of EMPA treatment.ResultsIn PCOS rats, EMPA decreased fat mass (21.1 ± 2.7 g vs 12.2 ± 0.8 g, p=0.0019), leptin (0.86 ± 0.16 ng/mL vs 0.45 ± 0.05 ng/mL, p&lt;0.05), and adiponectin (19.2 ± 1.3 mg/mL vs 14.4 ± 1.0 mg/mL, p&lt;0.05) and increased glucosuria (89 ± 8 mg/dL vs 4065± 400 mg/dL, p &lt; 0.0001). In PCOS rats, EMPA did not affect BW (309.0 ± 11.0 g vs 293.7 ± 6.1 g, p=0.6288), cumulative FI (251.8 ± 8.5 g vs 261.1 ± 6.5 g, p=0.8123), or lean mass. In PCOS rats, EMPA did not affect fasting glycemia, fasting insulin (17.6 ± 1.3 mU/mL, p= vs 18.0 ± 1.7 mU/mL, p=0.9922), or insulin sensitivity through the quantitative insulin‐sensitivity check index (0.302 ± 0.003 vs 0.299 ± 0.003, p=0.8615). While causing increased glucosuria in PBO rats, EMPA did not affect fat mass, BW, cumulative food intake, lean mass, fasting glycemia, or insulin sensitivity.In summary, SGLT‐2 inhibition had beneficial effects on fat mass and leptin in PCOS‐like rats. This occurred in the absence of changes in food intake, fasting glycemia, and insulin sensitivity. This suggests that SGLT‐2 inhibition is exerting a positive impact on the cardiometabolic profile in female hyperandrogenemia via more than excessive loss of glucose in the urine alone. Therefore, EMPA could be a novel therapeutic approach to treat obesity in PCOS women to ameliorate the adverse cardiometabolic profile associated with this pathology.Support or Funding InformationAHA 0830239N and 12SDG8980032, EFFERG, and NIH R21 DK‐113500 and P20 GM‐121334

The effects of daily fasting hours on shaping gut microbiota in mice

BackgroundIt has recently been reported that intermittent fasting shapes the gut microbiota to benefit health, but this effect may be influenced to the exact fasting protocols. The purpose of this study was to assess the effects of different daily fasting hours on shaping the gut microbiota in mice. Healthy C57BL/6 J male mice were subjected to 12, 16 or 20 h fasting per day for 1 month, and then fed ad libitum for an extended month. Gut microbiota was analyzed by 16S rRNA gene-based sequencing and food intake was recorded as well.ResultsWe found that cumulative food intake was not changed in the group with 12 h daily fasting, but significantly decreased in the 16 and 20 h fasting groups. The composition of gut microbiota was altered by all these types of intermittent fasting. At genus level, 16 h fasting led to increased level of Akkermansia and decreased level of Alistipes, but these effects disappeared after the cessation of fasting. No taxonomic differences were identified in the other two groups.ConclusionsThese data indicated that intermittent fasting shapes gut microbiota in healthy mice, and the length of daily fasting interval may influence the outcome of intermittent fasting.

Maternal Choline Intake Programs Hypothalamic Energy Regulation and Later-Life Phenotype of Male Wistar Rat Offspring.

High-folic-acid diets during pregnancy result in obesity in the offspring, associated with altered DNA-methylation of hypothalamic food intake neurons. Like folic acid, the methyl-donor choline modulates foetal brain development, but its long-term programing effects on energy regulation remain undefined. This study aims to describe the effect of choline intake during pregnancy on offspring phenotype and hypothalamic energy-regulatory mechanisms. Wistar rat dams are fed an AIN-93G diet with recommended choline (RC, 1 g kg-1 diet), low choline (LC, 0.5-fold), or high choline (HC, 2.5-fold) during pregnancy. Male pups are terminated at birth and 17 weeks post-weaning. Brain 1-carbon metabolites, body weight, food intake, energy expenditure, plasma hormones, and protein expression of hypothalamic neuropeptides are measured. HC pups have higher expression of the orexigenic neuropeptide-Y neurons at birth, consistent with higher cumulative food intake and body weight gain post-weaning compared to RC and LC offspring. LC pups have lower leptin receptor expression at birth and lower energy expenditure and activity during adulthood. Choline content of diets that are consumed by rats during pregnancy affects the later-life phenotype of offspring, associated with altered in utero programing of hypothalamic food intake regulation.

Metabolic effects of the dietary monosaccharides fructose, fructose-glucose, or glucose in mice fed a starch-containing moderate high-fat diet.

Fructose consumption has been linked to obesity and increased hepatic de novo lipogenesis (DNL). Excessive caloric intake often confounds the results of fructose studies, and experimental diets are generally low‐fat diets, not representative for westernized diets. Here, we compared the effects of dietary fructose with those of dietary glucose, in adult male and female mice on a starch‐containing moderate high–fat (HF) diet. After 5 weeks fattening on a HF high‐glucose (HF‐G) diet, mice were stratified per sex and assigned to one of the three intervention diets for 6 weeks: HF high fructose (HF‐F), HF with equimolar glucose and fructose (HF‐GF), or HF‐G. Bodyweight (BW) and food intake were measured weekly. Indirect calorimetry was performed on week 5; animals were sacrificed in food‐deprived state on week 6. Data were analyzed within sex. BW gain was similar among animals on the HF‐G, HF‐GF, and HF‐F diets. Cumulative food intake was slightly lower in HF‐F animals (both sexes). However, energy expenditure was not affected, or were circulating insulin and glucose concentrations, and hepatic triglyceride levels at endpoint. Hepatic gene expression analysis showed only minor alterations in hexokinase and glycolysis‐related expression in males, and no alterations in sugar transporters, or DNL‐related enzymes. In females, no consistent alterations in hepatic or small intestine gene expression were seen. Concluding, partial or complete replacement of dietary glucose with fructose does not increase caloric intake, and does not affect BW, hepatic triglyceride levels, or insulin concentrations in male and female mice on a moderate high–fat diet.

Chronic apelin analogue administration is more effective than established incretin therapies for alleviating metabolic dysfunction in diabetic db/db mice

Stable apelin-13 peptide analogues have shown promising acute antidiabetic effects in mice with diet-induced obesity diabetes. Here the efficacy of (pGlu)apelin-13 amide (apelin amide) and the acylated analogue (pGlu)(Lys8GluPAL)apelin-13 amide (apelin FA), were examined following chronic administration in db/db mice, a genetic model of degenerative diabetes. Groups of 9-week old male db/db mice (n = 8) received twice daily injections (09:00 and 17:00 h; i.p.) or saline vehicle, apelin amide, apelin FA, or the established incretin therapies, exendin-4(1–39) or liraglutide, all at 25 nmol/kg body weight for 21 days. Control C57BL/6J mice were given saline twice daily. No changes in body weight or food intake were observed with either apelin or liraglutide treatments, but exendin-4 showed a reduction in cumulative food intake (p < 0.01) compared with saline-treated db/db mice. Apelin analogues and incretin mimetics induced sustained improvements of glycaemia (p < 0.05 to p < 0.001, from day 9–21), lowered HbA1c at 21 days (p < 0.05) and raised plasma insulin concentrations. The treatments also improved OGTT and ipGTT with enhanced insulin responses compared with saline-treated control db/db mice (p < 0.05 to p < 0.001). Apelin amide was superior to incretin mimetics in lowering plasma triglycerides by 34% (p < 0.05). Apelin analogues unlike both incretin mimetics reduced pancreatic α-cell area (p < 0.05 to p < 0.01) and all peptide treatments enhanced pancreatic insulin content (p < 0.05 to p < 0.01). In conclusion, longer-term administration of apelin-13 analogues, induced similar and in some respects more effective metabolic improvements than incretin mimetics in db/db mice, providing a viable alternative approach for counteracting metabolic dysfunction for mild and more degenerative forms of the disease.

Engineering a protease-based and site-specific PEGylation-based strategy for the controlled release of exenatide.

Using the commercially available antidiabetic drug exenatide (exendin-4) as a model peptide, we designed a novel exenatide derivative, termed LEX-1, comprising a 12-mer albumin-binding peptide, a protease-sensitive linker and a native exenatide. In addition, site-specific PEGylation was performed using LEX-1 as a lead sequence to generate four exenatide derivatives (LEX-2 to LEX-5). Moreover, we determined the optimal molecular weight of maleimide-derivatized PEG for the site-specific PEGylation of LEX-1 by an in vitro stability assay and an in vivo hypoglycemic efficacy test. As a result, LEX-3 (PEG10 kDa) exerted enhanced proteolytic stability, rational release rate of free exenatide and the best glucose-stabilizing capability compared with others. In addition, the prolonged hypoglycemic effects of LEX-1 and LEX-3 were demonstrated in type 2 diabetic mice by multiple OGTTs and a hypoglycemic duration test. Furthermore, a pharmacokinetic test was conducted using Sprague Dawley (SD) rats; LEX-3 (PEG10 kDa) showed the best circulating t1/2 of ∼119.7 h for exenatide release from LEX-3, suggesting that LEX-3 has the potential to be developed into a once-weekly antidiabetic agent. The consecutive 8 week treatment of both LEX-1 and LEX-3 exhibited enhanced beneficial efficacies on body weight gain, cumulative food intake, % fat and hemoglobin A1c (HbA1c) reduction compared with exenatide treatment. Meanwhile, the chronic administration of LEX-1 and LEX-3 also effectively improved the blood biochemical indexes. Our results indicate the enhanced antidiabetic effects of LEX-1 and LEX-3, and our strategy of PEGylation and albumin conjugation can be applied to other bioactive agents.

Interaction Between Oxytocin and Opioidergic System on Food Intake Regulation in Neonatal Layer Type Chicken

The aim of the current study was to determine possible interaction of central oxytocin and opioidergic system on food intake regulation in neonatal layer-type chicken. In experiment 1, FD3 chicken ICV injected with control solution, oxytocin (10 µg), β-FNA (µ receptor antagonist, 5 µg) and oxytocin (10 µg) + β-FNA were injected. Experiments 2–6 were similar to experiments 1, except chicken injected with nor-BNI (κ receptor antagonist, 5 µg), NTI (δ receptor antagonist, 5 µg), DAMGO (µ receptor agonist, 62.25 pmol), U-50488H (κ receptor agonist, 10 nmol), DPDPE (δ receptor agonist, 20 pmol) instead of β-FNA. In experiment 7, control solution, DAMGO (125 pmol), d(CH2)5Tyr(Me)-[Orn8]-vasotocin (oxytocin antagonist, 5 µg) and DAMGO + d(CH2)5Tyr(Me)-[Orn8]-vasotocin were ICV injected to FD3 chicken. Experiments 8 and 9 were similar to experiments 7, except chicken injected with U-50488H (30 nmol) and DPDPE (40 pmol) instead of DAMGO. Then, cumulative food intake was recorded at 30, 60 and 120 min after injection. According to the results, ICV injection of the oxytocin (10 µg) significantly decreased food intake compared to control group (P < 0.05). Co-injection of the oxytocin + β-FNA and oxytocin + U-50488H significantly decreased hypophagic effect of the oxytocin (P < 0.05). While, co-injection of the oxytocin + nor-BNI or oxytocin + DAMGO significantly amplified hypophagic effect of the oxytocin in chicken (P < 0.05). In addition, ICV injection of DAMGO (125 pmol) significantly decreased cumulative food intake compared to control group (P < 0.05). However, co-addministration of the DAMGO + (CH2)5Tyr(Me)-[Orn8]-vasotocin significantly decreased hypophagic effect of the DAMGO (P < 0.05) in chicken. These results suggested there are interconnection between oxytocin and opioidergic system on central food intake regulation, which mediates via µ and κ opioidergic receptors in neonatal layer-type chicken.

Z-505, an Oral Ghrelin Receptor Agonist, Attenuates Anorexia After Total Gastrectomy in Rats

BackgroundAnorexia is a serious problem in patients with gastric cancer who have undergone gastrectomy. Ghrelin, an orexigenic hormone primarily secreted from the stomach, has been proposed to prevent anorexia. Significant reduction in plasma ghrelin levels after gastrectomy may contribute to lack of appetite and weight loss. In this study, we investigated the effects of Z-505, a ghrelin receptor agonist, on anorexia after total gastrectomy (TG) in a rat model. Methods and materialsMale Sprague–Dawley rats were used to establish a TG model, and then sham-operated (control) and TG rats were randomly assigned to four subgroups receiving administration of Z-505 (100 mg/kg, p.o., once daily) or vehicle for 14 d from day 14 to day 27 after TG. The food intake, body weight, and fat weight were evaluated during the test period. Moreover, the neuronal activity in the hypothalamus was evaluated on day 21 to investigate the mechanism of action of Z-505. ResultsIn TG rats, Z-505 significantly improved the decrease in cumulative food intake induced by the surgery over 14 d (TG + vehicle; 213.8 ± 15.3 g, n = 12 versus TG + Z-505; 258.2 ± 13.1 g, n = 14, P < 0.05). Z-505 also significantly increased fat weight and had a milder effect on body weight over 14 d. In addition, Z-505 significantly increased the number of c-Fos-positive cells in the hypothalamic arcuate nucleus (TG + vehicle; 17.8 ± 2.0, n = 12 versus TG + Z-505; 72.2 ± 11.8, n = 12, P < 0.001). ConclusionsZ-505 may be a useful therapeutic treatment for anorexia after TG.

Peripheral nerve block versus systemic analgesia in dogs undergoing tibial plateau levelling osteotomy: Analgesic efficacy and pharmacoeconomics comparison

ObjectiveTo compare the perioperative effects and pharmacoeconomics of peripheral nerve blocks (PNBs) versus fentanyl target-controlled infusion (fTCI) in dogs undergoing tibial plateau levelling osteotomy (TPLO). Study designRandomized clinical study. AnimalsA total of 39 dogs undergoing unilateral TPLO. MethodsAfter acepromazine and methadone, anaesthesia was induced with propofol and maintained with isoflurane. Dogs were allocated to group fTCI [target plasma concentration (TPC) 1 ng mL–1] or group PNB (nerve stimulator-guided femoral-sciatic block using 0.2 and 0.1 mL kg–1 of levobupivacaine 0.5%, respectively). If nociceptive response occurred, isoflurane was increased by 0.1%, and TPC was increased by 0.5 ng mL–1 in group fTCI; a fentanyl bolus (1 μg kg–1) was administered in group PNB. During the first 24 postoperative hours, methadone (0.2 mg kg–1) was administered intramuscularly according to the Short Form Glasgow Composite Pain Scale, or if pain was equal to 5/24 or 4/20 for two consecutive assessments, or if the dog was non-weight bearing. The area under the curve (AUC) of pain scores, cumulative postoperative methadone requirement, food intake and pharmacoeconomic implications were calculated. ResultsIncidence of bradycardia (p = 0.025), nociceptive response to surgery (p = 0.041) and AUC of pain scores (p < 0.0001) were greater in group fTCI. Postoperatively, 16/19 (84.2%) and eight/20 (40%) dogs in groups fTCI and PNB, respectively, were given at least one dose of methadone (p = 0.0079). Food intake was greater in group PNB (p = 0.049). Although total cost was not different (p = 0.083), PNB was more cost-effective in dogs weighing >15 kg. Conclusions and clinical relevanceCompared with group fTCI, incidence of bradycardia, nociceptive response to surgery, postoperative pain scores, cumulative methadone requirement were lower, and food intake was greater in group PNB, with an economic advantage in dogs weighing >15 kg.

A Novel Automated System Yields Reproducible Temporal Feeding Patterns in Laboratory Rodents

ABSTRACTBackgroundThe impact of temporal feeding patterns remains a major unanswered question in nutritional science. Progress has been hampered by the absence of a reliable method to impose temporal feeding in laboratory rodents, without the confounding influence of food-hoarding behavior.ObjectiveThe aim of this study was to develop and validate a reliable method for supplying crushed diets to laboratory rodents in consistent, relevant feeding patterns for prolonged periods.MethodsWe programmed our experimental feeding station to deliver a standard diet [StD; Atwater Fuel Energy (AFE) 13.9% fat] or high-fat diet (HFD; AFE 45% fat) during nocturnal grazing [providing 1/24th of the total daily food intake (tdF/I) of ad libitum–fed controls every 30 min] and meal-fed (3 × 1-h periods of ad libitum feeding) patterns in male rats (Sprague-Dawley: 4 wk old, 72–119 g) and mice [C57/Bl6J wild-type (WT): 6 mo old, 29–37 g], and ghrelin-null littermates (Ghr−/−; 27–34 g).ResultsGrazing yielded accurate, consistent feeding events in rats, with an approximately linear rise in nocturnal cumulative food intake [tdF/I (StD): 97.4 ± 1.5% accurate compared with manual measurement; R2 = 0.86; tdF/I (HFD): 99.0 ± 1.4% accurate; R2 = 0.86]. Meal-feeding produced 3 nocturnal meals of equal size and duration in StD-fed rats (tdF/I: 97.4 ± 0.9% accurate; R2 = 0.90), whereas the second meal size increased progressively in HFD-fed rats (44% higher on day 35 than on day 14; P < 0.01). Importantly, cumulative food intake in grazing and meal-fed rats was identical. Similar results were obtained in WT mice except that less restricted grazing induced hyperphagia (compared with meal-fed WT mice; P < 0.05 from day 1). This difference was abolished in Ghr−/− mice, with meal initiation delayed and meal duration enhanced. Neither pattern elevated corticosterone secretion in rats, but meal-feeding aligned ultradian pulses.ConclusionsWe have established a consistent, measurable, researcher-defined, stress-free method for imposing temporal feeding patterns in rats and mice. This approach will facilitate progress in understanding the physiologic impact of feeding patterns.

Photoperiodic changes in adiposity increase sensitivity of female Siberian hamsters to systemic VGF derived peptide TLQP-21.

TLQP-21, a peptide encoded by the highly conserved vgf gene, is expressed in neuroendocrine cells and has been the most prominent VGF-derived peptide studied in relation to control of energy balance. The recent discovery that TLQP-21 is the natural agonist for the complement 3a receptor 1 (C3aR1) has revived interest in this peptide as a potential drug target for obesity. We have investigated its function in Siberian hamsters (Phodopus sungorus), a rodent that displays natural seasonal changes in body weight and adiposity as an adaptation to survive winter. We have previously shown that intracerebroventricular administration of TLQP-21 reduced food intake and body weight in hamsters in their long-day fat state. The aim of our current study was to determine the systemic actions of TLQP-21 on food intake, energy expenditure and body weight, and to establish whether adiposity affected these responses. Peripheral infusion of TLQP-21 (1mg/kg/day for 7 days) in lean hamsters exposed to short photoperiods (SP) reduced cumulative food intake in the home cage (p<0.05), and intake when measured in metabolic cages (P<0.01). Energy expenditure was significantly increased (p<0.001) by TLQP-21 infusion, this was associated with a significant increase in uncoupling protein 1 mRNA in brown adipose tissue (BAT) (p<0.05), and body weight was significantly reduced (p<0.05). These effects of systemic TLQP-21 treatment were not observed in hamsters exposed to long photoperiod (LP) with a fat phenotype. C3aR1 mRNA and protein were abundantly expressed in the hypothalamus, brown and white adipose tissue in hamsters, but changes in expression cannot explain the differential response to TLQP-21 in lean and fat hamsters.

The effects of chronic oxytocin administration on body weight and food intake in DHT-induced PCOS model rats

Polycystic ovary syndrome (PCOS) is commonly associated with metabolic disorders, which are exacerbated by obesity. Recent studies have revealed that oxytocin contributes to metabolic, appetite, and body weight regulation. In the present study, we evaluated the effects of chronic administration of oxytocin on body weight, food intake, and fat mass in a dihydrotestosterone-induced rat model of PCOS. Body weight, body weight change, and relative cumulative food intake were significantly lower in the oxytocin-treated PCOS rats than in the vehicle-treated control PCOS rats. Similarly, visceral adipocyte size was significantly smaller in the oxytocin-treated PCOS rats than in the vehicle-treated control PCOS rats. On the other hand, the numbers of cystic follicles in the ovary did not differ between the two groups. The chronic administration of oxytocin did not affect the rats’ serum aspartate aminotransferase, alanine aminotransferase, or lactate dehydrogenase levels, indicating that it does not have adverse effects on hepatic function. These findings suggest that oxytocin could be a candidate drug for preventing the onset of obesity-related metabolic disorders in PCOS patients.

Role of Central Cannabinoidergic System on Ghrelin-Induced Hypophagia in Layer-Type Neonatal Chicken

Background: Feeding behavior is regulated via a complex network which interacts through diverse signals from central and peripheral tissues. OBJECTIVES: The main purpose of the current study was to determine the role of central cannabinoidergic (CBergic) system on ghrelin-induced hypophagia in 3-h food deprived (FD3) neonatal chicken. METHODS: In experiment 1, chicks were ICV injected with control solution, ghrelin (0.6 nmol), SR141716A (selective CB1 receptors antagonist, 6.25 µg) and ghrelin + SR141716A. In experiment 2, chickens received ICV injection of (A) control solution, ghrelin (0.6 nmol), AM630 (selective CB2 receptors antagonist, 1.25 µg) and ghrelin + AM630. In experiment 3, chickens were ICV injected with control solution, 2-AG (selective CB1 receptors agonist, 2µg), GSK1614343 (selective ghrelin receptors antagonist, 6 nmol) and 2-AG + GSK1614343. In experiment 4, the birds received control solution, CB65 (selective CB2 receptors agonist, 6.25 µg), CB65 + GSK1614343. Then the cumulative food intake was measured until 120 min post injection. RESULTS: According to the results, ICV injection of the ghrelin, significantly decreased cumulative food intake (P<0.05). Co-injection of the ghrelin + SR141716A and/or ghrelin + AM630 significantly amplified ghrelin-induced hypophagia compared to control group (P<0.05). Hyperphagia observed by ICV injection of the 2-AG (2 µg) (P<0.05). Co-injection of the 2-AG + GSK1614343 increased food intake compared to control group (P<0.05). ICV injection of the CB65 (1.25 µg) significantly increased food intake (P<0.05). Also, co-injection of the CB65 + GSK1614343 significantly amplified cumulative food intake in FD3 neonatal layer-type chicken (P<0.05). CONCLUSIONS: These results suggested ghrelin-induced hypophagia mediates via CB1 and CB2 receptors in neonatal layer-type chicken

Combined Exercise and Leucine Supplementation Promotes Skeletal Muscle Protein Deposition in Tumor Bearing Mice

PURPOSE: To investigate the effect of concurrent exercise training and leucine supplementation on skeletal muscle protein deposition in Colon 26 tumor bearing mice. METHODS: Male BALB/c mice were divided into a control group (C, n=8), a C26 tumor bearing group (T, n=8) and a tumor bearing plus exercise and leucine supplementation group (TEL, n=8). Mice in the C and T groups were fed with normal chow diet, while mice in the TEL group were fed with formulated diet contained 5% leucine and received 30-min swimming training 3 days per week (Monday, Wednesday and Friday) and resistance training 3 days per week (Tuesday, Thursday and Saturday) for 2 weeks. At 24 hours after the last training session, blood and gastrocnemius muscle samples were collected under full anesthesia. The contents of TNF-α and IL-6 in gastrocnemius muscle and serum were determined by ELISA. maximal grip strength was measured with a commercial grip strength meter. Two-way ANOVAs and post-hoc tests were used for data analysis. RESULTS: After tumor bearing, cumulative food intake appeared to decrease, whereas body weight (20.7 g vs. 26.1 g), wet gastrocnemius muscle weight (97.3 mg vs. 128.9 mg), total protein content (35.7 mg/g vs. 51.2 mg/g), sarcoplasmic protein content (26.5 mg/g vs. 38.3 mg/g), myofibrillar protein content (28.6 mg/g vs. 43.3 mg/g) and muscle strength (82.7 g vs. 156.5 g) were significantly lower in the T group than in the C group (all p<0.01). TNF-α and IL-6 contents in serum and gastrocnemius were obviously higher in the T group than in the C group (p<0.01). After exercise and leucine supplementation, cumulative food intake and the TNF-α and IL-6 content were significantly lower in the TEL group than in the T group (p<0.05), while body weight (21.8 g), wet gastrocnemius muscle weight (111.1 mg), total protein content (40.3 mg/g), sarcoplasmic protein content (30.7 mg/g), myofibrillar protein content (34.0 mg/g) and muscle strength (112.2 g) were significantly higher in the TEL group than in the T group (p<0.05 to p<0.01). CONCLUSIONS: Combined exercise and leucine supplementation significantly ameliorated skeletal muscular protein deposition in C26 tumor bearing mice, which may be through down-regulating the inflammatory response. (Supported by Research Foundation of Sichuan Provincial Department of Education grant #18ZB0106).

Effects of White Potato Preparation on Subjective Appetite, Food Intake and Glycemic Response in Healthy Older Adults (P08-083-19)

ObjectivesAlthough some epidemiological studies have linked potato consumption to obesity, diabetes, and mortality, there are limited studies on the effects of potatoes on appetite, food intake, and glycemic regulation in older adults. Therefore, the objective was to compare the effects of white potato preparation on subjective appetite, short-term food intake, and glycemic response in healthy older adults (>65 y). MethodsUsing a within-subject, repeated-measures design, 20 participants (age: 70.5 ± 0.7 y; BMI: 24.2 ± 0.6 kg/m2) completed five treatment conditions. Following an overnight fast, participants completed five treatment conditions (∼283 kcal) of baked potatoes, mashed potatoes, fried French fries, white bread, or continued to fast. Treatment meals were matched for available carbohydrates (33.1 g) and total fat (13.7 g). Subjective appetite and glycemic response were measured at baseline and over 120 min post-meal consumption using visual analogue scales and capillary blood samples, respectively. An ad libitum pizza lunch was provided to measure food intake at 120 min. ResultsChange from baseline subjective appetite and subjective appetite incremental area under the curve (iAUC) were lower after all treatment meals compared with meal skipping (P < 0.01). Ad libitum pizza lunch food intake was lower after all treatment meals compared with meal skipping by 175–215 kcal (P < 0.02). However, cumulative food intake (treatment meal + ad libitum food intake) did not differ among test conditions (P = 0.26). Change from baseline blood glucose and blood glucose iAUC were higher after all treatment meals compared with meal skipping (P < 0.001), but did not differ from each other. ConclusionsWhite potatoes suppressed subjective appetite and short-term food intake compared with meal skipping, suggesting that white potatoes do not bypass regulatory control mechanisms of energy intake in healthy older adults. Funding SourcesAlliance for Potato Research & Education.