Comparison of ventromedial and paraventricular lesions in rats that become obese

1986 ◽  
Vol 251 (6) ◽  
pp. R1221-R1227 ◽  
Author(s):  
K. Tokunaga ◽  
M. Fukushima ◽  
J. W. Kemnitz ◽  
G. A. Bray

Lesions in the ventromedial hypothalamus (VMH) uniformly produced obesity, but lesions in the paraventricular nucleus (PVN) produced obesity in only half of the animals. The obesity in the PVN-lesioned animals was related to the extent of PVN damage and was attenuated by concurrent damage to the dorsomedial nucleus. Comparing the PVN-lesioned rats that became obese with the VMH-lesioned rats that showed comparable weight gain, revealed several differences. The nocturnal intake of food in rats eating ad libitum was lower in the VMH-lesioned rats. Glucose concentrations were also lower in the VMH-lesioned rats, whether eating ad libitum or pair fed. Insulin concentrations were higher in the fatter animals fed ad libitum regardless of the location of the lesion. After pair feeding the insulin values were lower in both VMH- and PVN-lesioned rats than in controls. The diurnal excursion of corticosterone was blunted by both hypothalamic lesions in rats fed ad libitum, but after pair feeding there was less distortion of the diurnal rhythm. These data show that the characteristics of obesity produced by PVN lesions differ from those resulting from VMH damage.

1990 ◽  
Vol 259 (3) ◽  
pp. R658-R661
Author(s):  
R. M. Black ◽  
K. L. Conover ◽  
H. P. Weingarten

This experiment evaluates the hypothesis that an accelerated rate of gastric emptying accounts for the hyperphagia and obesity after lesions of the ventromedial hypothalamus (VMH). Gastric emptying was measured for 16 days after the production of VMH lesions in rats maintained either ad libitum or on restricted eating. Only ad libitum VMH-lesioned rats demonstrated faster than normal rates of emptying. However, VMH rats maintained at control weights showed normal rates of gastric emptying and, even in ad libitum rats, accelerated emptying was not apparent immediately after lesions. These findings indicate that changes of emptying are not a primary effect of VMH lesions but that this dysfunction develops secondarily as a consequence of excess eating and weight gain. Measurement of stomach secretions demonstrated, however, that VMH lesions did result in an immediate and direct effect on gastric secretion. These findings mitigate the importance of gastric emptying in the etiology of the VMH syndrome. Other data consistent with this conclusion are reviewed.


2004 ◽  
Vol 286 (4) ◽  
pp. R771-R778 ◽  
Author(s):  
Barry E. Levin ◽  
Ambrose A. Dunn-Meynell

The effects of running wheel exercise and caloric restriction on the regulation of body weight, adiposity, and hypothalamic neuropeptide expression were compared in diet-induced obese male rats over 6 wk. Compared with sedentary controls, exercising rats had reduced body weight gain (24%), visceral (4 fat pads; 36%) and carcass (leptin; 35%) adiposity but not insulin levels. Hypothalamic arcuate nucleus (ARC) proopiomelanocortin (POMC) mRNA expression was 25% lower, but ARC neuropeptide Y (NPY), agouti-related peptide, dorsomedial nucleus (DMN) NPY, and paraventricular nucleus (PVN) corticotropin-releasing hormone (CRH) expression was comparable to controls. Sedentary rats calorically restricted to 85% of control body weight reduced their visceral adiposity (24%), leptin (64%), and insulin (21%) levels. ARC NPY (23%) and DMN NPY (60%) were increased, while ARC POMC (40%) and PVN CRH (14%) were decreased. Calorically restricted exercising rats ran half as much as ad libitum-fed exercising rats and had less visceral obesity than comparably restricted sedentary rats. When sedentary restricted rats were refed after 4 wk, they increased intake and regained the weight gain and adiposity of sedentary controls. While refed exercising rats and sedentary rats ate comparable amounts, refed exercising rats regained weight and adiposity only to the level of ad libitum-fed exercising rats. Thus exercise lowers the defended level of weight gain and adiposity without a compensatory increase in intake and with a very different profile of hypothalamic neuropeptide expression from calorically restricted rats. This may be due to exercise-related factors other than plasma insulin and leptin.


Endocrinology ◽  
2002 ◽  
Vol 143 (12) ◽  
pp. 4513-4519 ◽  
Author(s):  
Csaba Fekete ◽  
Sumit Sarkar ◽  
William M. Rand ◽  
John W. Harney ◽  
Charles H. Emerson ◽  
...  

Abstract Neuropeptide Y (NPY) is one of the most important hypothalamic-derived neuropeptides mediating the effects of leptin on energy homeostasis. Central administration of NPY not only markedly stimulates food intake, but simultaneously inhibits the hypothalamic-pituitary-thyroid axis (HPT axis), replicating the central hypothyroid state associated with fasting. To identify the specific NPY receptor subtypes involved in the action of NPY on the HPT axis, we studied the effects of the highly selective Y1 ([Phe7,Pro34]pNPY) and Y5 ([chicken pancreatic polypeptide1–7, NPY19–23, Ala31, Aib32 (aminoisobutyric acid), Q34]human pancreatic polypeptide) receptor agonists on circulating thyroid hormone levels and proTRH mRNA in hypophysiotropic neurons of the hypothalamic paraventricular nucleus. The peptides were administered continuously by osmotic minipump into the cerebrospinal fluid (CSF) over 3 d in ad libitum-fed animals and animals pair-fed to artificial CSF (aCSF)-infused controls. Both Y1 and Y5 receptor agonists nearly doubled food intake compared with that of control animals receiving aCSF, similar to the effect observed for NPY. NPY, Y1, and Y5 receptor agonist administration suppressed circulating levels of thyroid hormones (T3 and T4) and resulted in inappropriately normal or low TSH levels. These alterations were also associated with significant suppression of proTRH mRNA in the paraventricular nucleus, particularly in the Y1 receptor agonist-infused group [aCSF, NPY, Y1, and Y5 (density units ± sem), 97.2 ± 8.6, 39.6 ± 8.4, 19.9 ± 1.9, and 44.6 ± 8.4]. No significant differences in thyroid hormone levels, TSH, or proTRH mRNA were observed between the agonist-infused FSanimals eating ad libitum and the agonist-infused animals pair-fed with vehicle-treated controls. These data confirm the importance of both Y1 and Y5 receptors in the NPY-mediated increase in food consumption and demonstrate that both Y1 and Y5 receptors can mediate the inhibitory effects of NPY on the HPT axis.


1988 ◽  
Vol 110 (3) ◽  
pp. 661-667 ◽  
Author(s):  
M. Freer ◽  
H. Dove ◽  
A. Axelsen ◽  
J. R. Donnelly

SummaryWeaned cross-bred lambs either grazed mature pasture or were confined to yards where they were offered material cut from ungrazed areas of the same pasture. A 1:2 mixture (on an air-dry basis) of sunflower meal and oat grain was offered for 81 days at 0, 200, 400 or 600 g/head or ad libitum. Individual estimates of intake of pasture and supplement by grazing sheep at four levels of supplementation were made on four adjacent plots.Weight gain increased from –30 to 178 g/day in the grazing animals as supplement intake increased up to 1030 g D.M./day and from –25 to 142 g/day in the yarded animals as supplement intake increased to 1076 g D.M./day. Growth of greasy wool increased from 4·5 to 11·7 g/day for grazing animals and from 4·5 to 10·2 g/day for those kept in yards.At levels of supplement intake below 400 g D.M./day, the intake of grazed pasture increased by up to 58% compared with unsupplemented animals. However, when the intake of supplement was increased to about 650 g D.M./day, pasture intake fell, with an estimated substitution rate of 1·1 g D.M. pasture per g D.M. supplement. At all levels of supplementation, the intake of hay by the yarded lambs was less than half the intake of herbage in the field. However, at levels of supplement intake between 300 and 500 g D.M./day, the substitution rate was similar to that measured in the grazing animals, suggesting that this is an attribute of roughage quality, rather than differential eating behaviour between grazing and yarded animals.The wastage, w (g D.M./day), of supplement was linearly related to the amount offered, s (g D.M./day), by the equationw = 0·263s − 38·8; R2 = 0·89Variability in supplement intake between individual grazing lambs was not affected by the level of supplementation but the coefficient of variation of supplement intake was considerably greater than that of the intake of unsupplemented pasture. Variability in the intake of pasture increased with the level of supplementation but variability in the total intake of food was similar at each level of supplement, indicating some degree of individual compensation in the intake of the two components.


2021 ◽  
pp. 097275312110057
Author(s):  
Archana Gaur ◽  
G.K. Pal ◽  
Pravati Pal

Background: Obesity is because of excessive fat accumulation that affects health adversely in the form of various diseases such as diabetes, hypertension, cardiovascular diseases, and many other disorders. Our Indian diet is rich in carbohydrates, and hence the sucrose-induced obesity is an apt model to mimic this. Ventromedial hypothalamus (VMH) is linked to the regulation of food intake in animals as well as humans. Purpose: To understand the role of VMHin sucrose-induced obesity on metabolic parameters. Methods: A total of 24 adult rats were made obese by feeding them on a 32% sucrose solution for 10 weeks. The VMH nucleus was ablated in the experimental group and sham lesions were made in the control group. Food intake, body weight, and biochemical parameters were compared before and after the lesion. Results: Male rats had a significant weight gain along with hyperphagia, whereas female rats did not have a significant weight gain inspite of hyperphagia. Insulin resistance and dyslipidemia were seen in both the experimental and control groups. Conclusion: A sucrose diet produces obesity which is similar to the metabolic syndrome with insulin resistance and dyslipidemia, and a VMH lesion further exaggerates it. Males are more prone to this exaggeration.


2021 ◽  
Vol 12 ◽  
Author(s):  
Alessio Basolo ◽  
Takafumi Ando ◽  
Douglas C. Chang ◽  
Tim Hollstein ◽  
Jonathan Krakoff ◽  
...  

ObjectiveCirculating albumin is negatively associated with adiposity but whether it is associated with increased energy intake, lower energy expenditure or weight gain has not been examined.MethodsIn study 1 (n=238; 146 men), we evaluated whether fasting albumin concentration was associated with 24-h energy expenditure and ad libitum energy intake. In study 2 (n=325;167 men), we evaluated the association between plasma albumin and change in weight and body composition.ResultsAfter adjustment for known determinants of energy intake lower plasma albumin concentration was associated with greater total daily energy intake (β= 89.8 kcal/day per 0.1 g/dl difference in plasma albumin, p=0.0047). No associations were observed between plasma albumin concentrations and 24-h energy expenditure or 24-h respiratory quotient (p>0.2). Over 6 years, volunteers gained on average 7.5 ± 11.7 kg (p<0.0001). Lower albumin concentrations were associated with greater weight [β=3.53 kg, p=0.039 (adjusted for age, sex, follow up time), CI 0.16 to 6.21 per 1 g/dl difference albumin concentration] and fat mass (β=2.3 kg, p=0.022), respectively, but not with changes in fat free mass (p=0.06).ConclusionsLower albumin concentrations were associated with increased ad libitum food intake and weight gain, indicating albumin as a marker of energy intake regulation.Clinical Trial RegistrationClinicalTrials.gov, identifiers NCT00340132, NCT00342732.


2017 ◽  
Vol 38 (2) ◽  
pp. 855 ◽  
Author(s):  
Daiane De Oliveira Grieser ◽  
Simara Márcia Marcato ◽  
Mariana Fátima Zanon Ferreira ◽  
Taciana Maria de Oliveira-Bruxel ◽  
Vittor Zancanela ◽  
...  

This study aimed to assess the effect of quantitative dietary restriction during refeeding on the performance, body chemical composition, and deposition, weight gain of organs and carcass parts of quails reared for meat (Coturnix coturnix coturnix). A total of 144 quails, between 11 to 42 days old, were distributed in a completely randomized design, 4x2 factorial scheme, at four levels of feed restriction (ad libitum, 30%, 50% and 70% restrictions on the daily intake ad libitum) for both genders. Therefore, there was eight treatments with three replicates and six birds each. At the tenth day of age, the animals were housed in cages, where remained for four days under adaptation. Dietary restriction was applied between the days 15 and 35 while refeeding was carried out from day 36 to 42. Compensatory weight gain (CWG), i.e. weight gain of organs and carcass parts, and feed efficiency (FE) were improved for quails under feed restriction. Fat (F), crude protein (CP), protein deposition rate (PDR) and fat in females (FDf) and carcass retained energy in females (CREf) increased linearly as restriction levels decreased. Maximum estimates of feed intake for males (MFIm), compensatory weight gain for males (CWGm) and females (CWGf), feed efficiency for males (FEm), protein deposition for males (PDm) and carcass retained energy in males (CREm) were obtained with restriction levels of 43.56%, 30.56%, 63.93%, 62.63%, 80.25%, 1.94% and 09.34% if compared to ad libitum, respectively. As a result, we concluded that according to quantitative feed restriction level, significant increases in feed efficiency and body weight gain, as well as decreases in carcass fat throughout quail refeeding period. As for gender, given the existing sexual dimorphism, females lost greater body weight than males under dietary restriction, besides showing higher protein and fat gains in the carcass and an enhanced feed efficiency during refeeding.


2019 ◽  
Vol 30 (1) ◽  
pp. 67-77.e3 ◽  
Author(s):  
Kevin D. Hall ◽  
Alexis Ayuketah ◽  
Robert Brychta ◽  
Hongyi Cai ◽  
Thomas Cassimatis ◽  
...  

Nutrients ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3893 ◽  
Author(s):  
Desiree M. Sigala ◽  
Adrianne M. Widaman ◽  
Bettina Hieronimus ◽  
Marinelle V. Nunez ◽  
Vivien Lee ◽  
...  

Sugar-sweetened beverage (sugar-SB) consumption is associated with body weight gain. We investigated whether the changes of (Δ) circulating leptin contribute to weight gain and ad libitum food intake in young adults consuming sugar-SB for two weeks. In a parallel, double-blinded, intervention study, participants (n = 131; BMI 18–35 kg/m2; 18–40 years) consumed three beverages/day containing aspartame or 25% energy requirement as glucose, fructose, high fructose corn syrup (HFCS) or sucrose (n = 23–28/group). Body weight, ad libitum food intake and 24-h leptin area under the curve (AUC) were assessed at Week 0 and at the end of Week 2. The Δbody weight was not different among groups (p = 0.092), but the increases in subjects consuming HFCS- (p = 0.0008) and glucose-SB (p = 0.018) were significant compared with Week 0. Subjects consuming sucrose- (+14%, p < 0.0015), fructose- (+9%, p = 0.015) and HFCS-SB (+8%, p = 0.017) increased energy intake during the ad libitum food intake trial compared with subjects consuming aspartame-SB (−4%, p = 0.0037, effect of SB). Fructose-SB decreased (−14 ng/mL × 24 h, p = 0.0006) and sucrose-SB increased (+25 ng/mL × 24 h, p = 0.025 vs. Week 0; p = 0.0008 vs. fructose-SB) 24-h leptin AUC. The Δad libitum food intake and Δbody weight were not influenced by circulating leptin in young adults consuming sugar-SB for 2 weeks. Studies are needed to determine the mechanisms mediating increased energy intake in subjects consuming sugar-SB.


1983 ◽  
Vol 36 (3) ◽  
pp. 445-451 ◽  
Author(s):  
M. J. Bryant ◽  
P. Rowlinson ◽  
H. A. M. Van der Steen

ABSTRACTNursing frequency, suckling duration and teat order were recorded in 12 ‘hybrid’ sows and their litters from parturition to weaning at day 42 post partum. Sows and their litters were moved from the farrowing quarters at day 20; half were housed as a group (G) and fed ad libitum with a boar present and the other half were housed individually (S) with no boar present and ration-fed to scale.Some differences occurred in behaviour from day 20. A significantly greater number of false nursing periods, significant synchronization of nursing periods, and a tendency for more long and short nursing intervals occurred in G than S sows and litters. The duration of the preliminary nosing phase and the total nursing period were significantly longer in S than G litters. Teat order scores, indicating consistency of piglet suckling position on the sow, tended to be greater in S than G litters, and there was a fall in the score for G litters in the weeks following grouping. This was associated with a check in live-weight gain.All G sows showed oestrus during lactation, on average 15 days after grouping. There was no incidence of lactational oestrus in the S sows which showed oestrus 5 days after weaning.


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