scholarly journals Involvement of M1 and M3 receptors in isolated pancreatic islets function during weight cycling in ovariectomized rats

2019 ◽  
Vol 97 (5) ◽  
pp. 647-654 ◽  
Author(s):  
Kayo Augusto Salandin Pacher ◽  
Thaís Furtado Camargo ◽  
Thiago Antonio Moretti Andrade ◽  
Helena Cristina Lima Barbosa-Sampaio ◽  
Maria Esméria Corezola do Amaral
Keyword(s):  
Adipose Tissue ◽  
Insulin Secretion ◽  
Caloric Intake ◽  
Ovariectomized Rats ◽  
Weight Cycling ◽  
Isolated Pancreatic Islets ◽  
Fasting Glycemia ◽  
Commercial Feed ◽  
M3 Receptors ◽  
Ad Libitum

We investigated the structural and functional adaptations of the pancreas during weight cycling in animals submitted to hypoestrogenism. Female Wistar rats were distributed among the following test groups: ShamAL (AL, ad libitum); OVXAL (ovariectomized); and OVXcycle (dietary restriction with weight cycling). The ShamAL and OVXAL groups received commercial feed ad libitum, whereas the OVXcycle group received 21 days of commercial feed ad libitum, and 21 days of caloric restriction, with caloric intake amounting to 40% of the amount of feed consumed by the rats in the OVXAL group. The tolerance tests for glucose and insulin were applied. After euthanasia, the pancreas and adipose tissue were collected. The disappearance of glucose during the insulin assay occurred at a higher rate in tissues from the OVXcycle group, compared with the OVXAL group. Fasting glycemia and perirenal adipose tissue were lower in the OVXcycle group. By comparison with the ShamAL and OVXAL groups, the OVXcycle group showed higher protein expression of the M1 and M3 receptors and SOD1–2, as well as higher carbachol-induced insulin secretion. Under highly stimulatory conditions with 16.7 mmol/L glucose, the OVXAL and OVXcycle groups presented lower insulin secretion compared with the ShamAL group. Morphological analysis revealed higher iron deposition in the OVXAL islets by comparison with the OVXcycle group. These results show that ovariectomy accelerated the loss of pancreatic islet function, and that weight cycling could restore the function of the islets.

scholarly journals Nutrient Responsive Nesfatin-1 Regulates Energy Balance and Induces Glucose-Stimulated Insulin Secretion in Rats

Endocrinology ◽  
2011 ◽  
Vol 152 (10) ◽  
pp. 3628-3637 ◽  
Author(s):  
R. Gonzalez ◽  
R. L. S. Perry ◽  
X. Gao ◽  
M. P. Gaidhu ◽  
R. G. Tsushima ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Insulin Secretion ◽  
Glucose Uptake ◽  
Pancreatic Islets ◽  
Whole Body ◽  
Isolated Pancreatic Islets ◽  
Brown Adipose ◽  
Glucose Stimulated Insulin Secretion ◽  
Body Energy

Nesfatin-1 is a recently discovered anorexigen, and we first reported nesfatin-like immunoreactivity in the pancreatic β-cells. The aim of this study was to characterize the effects of nesfatin-1 on whole-body energy homeostasis, insulin secretion, and glycemia. The in vivo effects of continuous peripheral delivery of nesfatin-1 using osmotic minipumps on food intake and substrate partitioning were examined in ad libitum-fed male Fischer 344 rats. The effects of nesfatin-1 on glucose-stimulated insulin secretion (GSIS) were examined in isolated pancreatic islets. L6 skeletal muscle cells and isolated rat adipocytes were used to assess the effects of nesfatin-1 on basal and insulin-mediated glucose uptake as well as on major steps of insulin signaling in these cells. Nesfatin-1 reduced cumulative food intake and increased spontaneous physical activity, whole-body fat oxidation, and carnitine palmitoyltransferase I mRNA expression in brown adipose tissue but did not affect uncoupling protein 1 mRNA in the brown adipose tissue. Nesfatin-1 significantly enhanced GSIS in vivo during an oral glucose tolerance test and improved insulin sensitivity. Although insulin-stimulated glucose uptake in L6 muscle cells was inhibited by nesfatin-1 pretreatment, basal and insulin-induced glucose uptake in adipocytes from nesfatin-1-treated rats was significantly increased. In agreement with our in vivo results, nesfatin-1 enhanced GSIS from isolated pancreatic islets at both normal (5.6 mm) and high (16.7 mm), but not at low (2 mm), glucose concentrations. Furthermore, nesfatin-1/nucleobindin 2 release from rat pancreatic islets was stimulated by glucose. Collectively, our data indicate that glucose-responsive nesfatin-1 regulates insulin secretion, glucose homeostasis, and whole-body energy balance in rats.

Depletion of linoleate induced by weight cycling is independent of extent of calorie restriction

1997 ◽  
Vol 272 (1) ◽  
pp. R43-R50 ◽  
Author(s):  
Z. Y. Chen ◽  
M. M. Sea ◽  
K. Y. Kwan ◽  
Y. H. Leung ◽  
P. F. Leung
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Calorie Restriction ◽  
Saturated Fatty Acids ◽  
Epidemiological Studies ◽  
Weight Cycling ◽  
Final Body Weight ◽  
Tissue Lipids ◽  
Ad Libitum ◽  
Triacylglycerol Species

Recent epidemiological studies have suggested that weight cycling induced by repeated dieting over time may increase the risk of cardiovascular disease. It is speculated that the increased mortality from coronary heart disease for people with a history of excessive weight cycling could be attributed to change in lipid metabolism. Previous studies have demonstrated that repeated cycling of 100% food restriction followed by ad libitum refeeding caused a depletion of linoleate and alpha-linolenate in rats. The objective of the present study was to test the hypothesis that the weight cycling-induced reduction in linoleate and alpha-linolenate is independent of extent of calorie restriction. Two consecutive weight cycles in three experiments were induced by 100% calorie restriction, 60% calorie restriction, and 36% calorie restriction, respectively, followed by ad libitum refeeding. As the consequence of the two weight cycles, linoleate and linolenate were decreased, whereas myristate, palmitate, and palmitoleate were proportionally increased in carcass and adipose tissue lipids. The results of all three experiments showed a preferential depletion of linoleate and alpha-linolenate without changes in final body weight, total body fat, and adipose tissue pads in the weight-cycled rats. In addition, the triacylglycerol species profile in the adipose tissue of weight-cycled rats was significantly remodeled, with a proportional depletion of linoleate-enriched triacylglycerol species (LLL, LLO, and LLP, where L, O, and P are linoleic, oleic, and palmitic acid, respectively) and a proportional accumulation of palmitate-enriched triacylglycerol species (OPPo, PPPo, and PPP, where Po is palmitoleic acid). We conclude that weight cycling changes the ratio of polyunsaturated fatty acids to saturated fatty acids and remodels the adipose tissue triacylglycerol species profile in rats.

Sex-related differences in energy balance in response to caloric restriction

2005 ◽  
Vol 289 (1) ◽  
pp. E15-E22 ◽  
Author(s):  
A. Valle ◽  
A. Català-Niell ◽  
B. Colom ◽  
F. J. García-Palmer ◽  
J. Oliver ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Adipose Tissue ◽  
Energy Balance ◽  
Caloric Restriction ◽  
Uncoupling Protein ◽  
Caloric Intake ◽  
Carbon Dioxide Production ◽  
Brown Adipose ◽  
Ad Libitum ◽  
Ad Libitum Intake

Sex-related differences in energy balance were studied in young Wistar rats fed standard chow pellets either ad libitum or in restricted amounts (60% of ad libitum intake) for 100 days. Caloric intake, indirect calorimetry, organ and adipose tissue weights, energy efficiency, liver mitochondrial respiration rate, and brown adipose tissue (BAT) uncoupling protein-1 (UCP1) content were measured. Ad libitum-fed females showed greater oxygen consumption (V̇o2) and carbon dioxide production (V̇co2) and lower energy efficiency than males. Caloric restriction induced a chronic drop of V̇o2 and V̇co2 in females but not in males over the period studied. Restricted females showed a better conservation of metabolic active organ mass and a greater decrease in adipose depots than restricted males. Moreover, changes of BAT size and UCP1 content suggest that BAT may be the main cause responsible for sex differences in the response of energy balance to caloric restriction. In conclusion, our results indicate that females under caloric restriction conditions deactivate facultative thermogenesis to a greater degree than males. This ability may have obvious advantages for female survival and therefore the survival of the species when food is limiting.

ACUTE REGULATION OF INSULIN RELEASE BY THE PITUITARY GLAND IN RELATION TO HYPERINSULINAEMIA AND OBESITY

1979 ◽  
Vol 81 (3) ◽  
pp. 271-279 ◽  
Author(s):  
ANNE BELOFF-CHAIN ◽  
S. BOGDANOVIC ◽  
M. A. CAWTHORNE
Keyword(s):  
Insulin Secretion ◽  
Pancreatic Islets ◽  
Gene Dosage ◽  
Caloric Intake ◽  
Insulin Level ◽  
Gene Dosage Effect ◽  
Isolated Pancreatic Islets ◽  
Gold Thioglucose ◽  
High Insulin ◽  
Pituitary Glands

The pituitary glands from mice rendered obese by gold thioglucose treatment and by dietary manipulation, and pituitary glands from lean mice after a high food intake or a glucose load, were shown to stimulate insulin secretion from isolated pancreatic islets. The insulin releasing activity of pituitary glands from obese (ob/ob) mice was reduced by fasting for 24 and 48 h. Results obtained with pituitary glands from ob/ob and from lean ob/ + and + /+ mice suggest that the insulin releasing property manifests a gene dosage effect. Pituitary glands from 3-week-old (young) ob/ob mice stimulated insulin secretion to the same extent as pituitary glands from 3-month-old (adult) ob/ob mice. The pancreatic islets of young ob/ob mice were shown to be somewhat more responsive to stimulation by the pituitary factor than were lean ob/ + or + / + islets from this age group. The concept that high insulin level, partly under pituitary control, and high caloric intake may be interlinked and may, in combination, be a major factor in producing obesity is discussed. Furthermore, it is suggested that the pituitary insulin releasing factor may play a role in the early development of obesity in the animal models studied.

Effects of endogenous GIP in patients with type 2 diabetes

2021 ◽  
Author(s):  
Signe Stensen ◽  
Lærke S Gasbjerg ◽  
Liva L. Krogh ◽  
Kirsa Skov-Jeppesen ◽  
Alexander H. Sparre-Ulrich ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Adipose Tissue ◽  
Insulin Secretion ◽  
Receptor Antagonist ◽  
Bone Homeostasis ◽  
Collagen Crosslinks ◽  
Ad Libitum ◽  
Postprandial Insulin ◽  
Gip Receptor

Objective: The insulinotropic effect of exogenous, intravenously infused glucose-dependent insulinotropic polypeptide (GIP) is impaired in patients with type 2 diabetes. We evaluated the effects of endogenous GIP in relation to glucose and bone metabolism in patients with type 2 diabetes using a selective GIP receptor antagonist and hypothesized that the effects of endogenous GIP were preserved. Design: A randomized, double-blinded, placebo-controlled, crossover study. Methods: Ten patients with overweight/obesity and type 2 diabetes (mean±SD; HbA1c 52±11 mmol/mol; BMI 32.5±4.8 kg/m2) were included. We infused a selective GIP receptor antagonist, GIP(3-30)NH2 (1,200 pmol × kg-1 × min-1), or placebo (saline) during two separate, 230-minute, standardized, liquid mixed meal tests followed by an ad libitum meal. Subcutaneous adipose tissue biopsies were analyzed. Results: Compared with placebo, GIP(3-30)NH2 reduced postprandial insulin secretion (Δbaseline-subtracted area under the curve (bsAUC)C-peptide%±SEM; -14±6%, p=0.021) and peak glucagon (Δ%±SEM; -11±6%, p=0.046), but had no effect on plasma glucose (p=0.692). Suppression of bone resorption (assessed by circulating carboxy-terminal collagen crosslinks (CTX)) was impaired during GIP(3-30)NH2 infusion compared with placebo (ΔbsAUCCTX;±SEM; -4.9±2 ng/ml × min, p=0.005) corresponding to a ~50% reduction. Compared with placebo, GIP(3-30)NH2 did not affect plasma lipids, ad libitum meal consumption or adipose tissue triglyceride content. Conclusions: Using a selective GIP receptor antagonist during a meal, we show that endogenous GIP increases postprandial insulin secretion with little effect on postprandial glycemia but is important for postprandial bone homeostasis in patients with type 2 diabetes.

Sex-specific differences in adipose tissue lipolysis during body weight cycling

2011 ◽  
Vol 6 (S 01) ◽  
Author(s):  
V Benz ◽  
M Bloch ◽  
A Foryst-Ludwig ◽  
C Böhm ◽  
R Winkler ◽  
...  
Keyword(s):  
Body Weight ◽  
Adipose Tissue ◽  
Weight Cycling ◽  
Adipose Tissue Lipolysis

Insulin secretion, body composition and pig performance are altered by feeding pattern

2014 ◽  
Vol 54 (3) ◽  
pp. 319 ◽  
Author(s):  
Ronald E. Newman ◽  
Jeffery A. Downing ◽  
Peter C. Thomson ◽  
Cherie L. Collins ◽  
David J. Henman ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Feed Intake ◽  
Plasma Insulin ◽  
Feeding Strategy ◽  
Growing Pigs ◽  
Carcass Composition ◽  
Production Performance ◽  
Feed Conversion ◽  
Ad Libitum ◽  
Entire Male

Three studies investigated the effect of feeding strategy on production performance and endocrine status of growing pigs. For Experiment 1, 20 entire male pigs (70.0 ± 4.6 kg) were allocated randomly to individual pens in one of four climate-controlled rooms. Pigs were fed for 23 days either ad libitum or entrained to feed bi-phasically for two 90-min periods. For Experiment 2, 20 entire male pigs (41.2 ± 3.5 kg) were housed as per Experiment 1. Pigs were fed for 49 days either ad libitum or fed bi-phasically for two 60-min periods. For Experiment 3, 100 female pigs (66.1 ± 3.5 kg) were randomly allocated to individual pens within a commercial piggery and fed for 42 days either ad libitum or bi-phasically for two 60-min periods. Ear vein catheters were inserted into 10 pigs from each group and hourly blood samples were collected for 24 h in Experiments 1 and 2 and for 11 h in Experiment 3. Plasma insulin, non-esterified fatty acid and glucose concentrations were determined in Experiments 1 and 2, and glucose and insulin concentrations in Experiment 3. Feed intake and performance were recorded in all experiments and carcass composition was assessed by computed tomography for Experiment 2. There were no differences in final liveweight between the two treatment groups for all experiments. Pigs fed for two 90-min periods (Experiment 1) showed no difference in feed intake when compared with feeding ad libitum. Pigs in Experiment 2 fed for two 60-min intervals consumed 2.49 kg/pig.day compared with those fed ad libitum that consumed 2.68 kg/day (P = 0.057). In Experiment 3, pigs fed twice daily consumed 2.82 kg/pig.day compared with 2.91 kg/pig.day in ad libitum-fed pigs (P = 0.051). Bi-phasic fed pigs in Experiment 2 had improved (P < 0.05) feed conversion efficiency compared with pigs fed ad libitum. For all experiments, there was no difference in plasma glucose concentrations between the two treatments. In all three experiments, the circulating insulin concentrations for pigs fed ad libitum remained at a constant level throughout the sampling period. However, plasma insulin concentrations for the bi-phasic fed pigs significantly increased ~1 h after both feeding periods during all three experiments. Insulin secretion of pigs fed for two 90-min periods differed from that of pigs fed for two 60-min periods. Plasma insulin concentration increased five-fold following feeding for 60 min, compared with that in pigs fed for 90 min, which increased two-fold. Bi-phasic-fed pigs from Experiment 2 had reduced (P < 0.05) total carcass fat and significantly increased muscle when compared with pigs fed ad libitum. The data showed that feeding pigs at two succinct periods aligned insulin secretion to the time of feeding. Pigs fed for 60 min, unlike those fed for 90-min intervals, had reduced feed intake in comparison to those fed ad libitum. This may suggest that the duration of the feeding bout is important for this response and this may in turn influence both energy balance and the way energy is partitioned.

Potability of sea water with special reference to the cat

1959 ◽  
Vol 196 (3) ◽  
pp. 633-641 ◽  
Author(s):  
A. V. Wolf ◽  
Phoebe G. Prentiss ◽  
Lillian G. Douglas ◽  
Russell J. Swett
Keyword(s):  
Special Reference ◽  
Water Deficit ◽  
Experimental Verification ◽  
Sea Water ◽  
Caloric Intake ◽  
Water Drinking ◽  
Ad Libitum

Under certain conditions in which food provides an adequate caloric intake but too little water to sustain a cat or a rat in euhydration, these animals can be shown to depend for survival on their intake of sea water. They will generally drink enough sea water ad libitum to thrive, even overcoming thereby a previously induced water deficit; or, they will readily eat their food, mixed with sea water in amounts which can vary widely, with similar benefit. Without sea water they undergo progressive hydropenia and die. Along with experimental verification of the potability of sea water a theory of sea water drinking (mariposia) is presented, based upon the concept of urinary osmotic space.

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