Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0028754 (obesity)
 124,988 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Increased hypothalamic neuropeptide Y levels have previously been demonstrated in several hypothalamic nuclei of the (fa/fa) Zucker rat. This study set out to characterise hypothalamic NPY receptors in both genotypres and to study the effect of exogenous NPY on feeding behavior in these rats. Spontaneous daytime food intake was raised in the obese rat (p less than 0.05). Total hypothalamic receptor density (Bmax) was reduced in the obese rat compared with the lean rat (by 56%, p less than 0.005), but affinity remained unaltered. The lowest dose of NPY tested (23.5 pmol) stimulated daytime feeding in lean rats after 1, 2 and 3 hours but was inaffective in the obese rat (p less than 0.05). At two higher doses (235 pmol and 2.35 nmol), NPY was equipotent in both genotypes over 1 and 2 hours but NPY-induced feeding was attenuated over 3 hours in the obese rat. These results suggest an overactive endogenous NPYergic system in the obese (fa/fa) rat which might contribute to hyperphagia and obesity in this strain.
 ...
PMID:Hypothalamic neuropeptide Y receptor characteristics and NPY-induced feeding responses in lean and obese Zucker rats. 165 13

The Prader-Willi (PWS) and Angelman syndromes (AS) share the same apparent cytogenetic and molecular lesions of 15q11-13 and yet exhibit distinct clinical phenotypes. The etiology of PWS or AS appears to depend on the parental origin of the aberrant chromosome 15. Substantial clinical overlap has not been reported between deletion-positive PWS and AS patients. In the present study, we report the clinical, cytogenetic, and molecular findings in three AS patients. The first patient is a mentally retarded woman with a visible deletion of 15q11-13 with typical craniofacial, behavioral, and neurologic changes of AS. This patient is hyperphagic, and she is moderately obese for her height. Her hands and feet are small. These manifestations are more characteristic of PWS and not of AS. The molecular studies showed deletions of maternal origin for five distal PWCR loci. The most proximal locus, D15S18, was not deleted. These findings are identical to those found in our third AS patient who does not have any PWS features. To the best of our knowledge, this is the first report of concurrence of hyperphagia with consequent obesity and the AS phenotype in a patient with a del 15(q11-13) of maternal origin. These clinical findings suggest that overlap in the symptoms of PWS and AS can occur. Our second AS patient presents with atypical molecular findings in that he cannot be classed into any of the three proposed sub-groups of AS patients and may be representative of a fourth sub-group of AS patients.
 ...
PMID:Molecular and clinical overlap of Angelman and Prader-Willi syndrome phenotypes. 168 91

Central and lateral hypothalamic concentrations of 9 regulatory peptides implicated in the control of feeding behaviour were measured in corpulent (cp/cp) JCR:LA-cp rats which develop spontaneous obesity, hyperinsulinaemia and hyperlipidaemia, and in lean (+/?) controls. In female cp/cp rats, central hypothalamic levels of neuropeptide Y (NPY), neurotensin, somatostatin and substance P were significantly lower (p less than 0.02) than in lean female controls. Following food restriction with a 16% reduction in body weight, these differences were apparently reversed and there were also significant rises in the lateral hypothalamic concentrations of neurotensin and of galanin. The other 4 peptides examined (bombesin, calcitonin gene-related peptide, neuromedin B and vasoactive intestinal peptide) did not differ significantly between cp/cp and lean females, either fed freely or food-restricted. Male cp/cp rats showed no significant differences from lean males in central or lateral hypothalamic concentrations of any of the 9 peptides. NPY and galanin are powerful and specific central appetite stimulants, whereas neurotensin, substance P and somatostatin inhibit feeding when injected centrally. Disturbances in these putative appetite-regulating peptides may be involved in the hyperphagia and other hypothalamic abnormalities in this spontaneous obesity syndrome. The apparent absence of differences between the male corpulent and lean groups may relate to sexual dimorphism of the syndrome, which is more marked in the females.
 ...
PMID:Hypothalamic regulatory peptide disturbances in the spontaneously obese JCR: LA-corpulent rat. 172 Mar 64

Twenty-four hour energy expenditure (24EE) can be measured in a respiratory chamber. 24EE is comprised of the basal metabolic rate, the thermic effect of food, and the energy cost of physical activity. The major determinant of 24EE, fat-free mass, accounts for approximately 80% of the variance observed between individuals. Genetic factors seem to be the cause of the familial aggregation of 24EE in man. The variability of 24EE for a given body size and composition is of importance because a low metabolic rate is a major risk factor for weight gain in man. There is increasing evidence that obesity, often an inherited disorder, cannot always be attributed to gluttony and sloth. Similar to the need to treat essential hypertension, there is a need to treat a disorder perhaps best called essential obesity.
 ...
PMID:A brief overview of human energy metabolism and its relationship to essential obesity. 172 37

This study was performed to examine the effect of overeating on in vivo and in vitro insulin secretion in normal mice. Six week old male CRJ-ICR mice were maintained on a cookie and chocolate mashed diet (C.C. diet) until 30 weeks of age; control mice received an ordinary mouse chow. The mice on the C.C. diet (C.C. mice) consumed 125-130% of the daily caloric intake of control mice throughout the study. C.C. mice developed mild hyperglycemia with relative obesity from 16 weeks of age. Fed blood glucose levels at 30 weeks of age for C.C. mice were 158.3 +/- 6.7 mg/dl as opposed to 127.2 +/- 3.1 mg/dl for controls (p less than 0.01). In experimental mice at 18 weeks of age, plasma insulin response after intraperitoneal glucose load (2 mg/g BW) and insulin secretion at 30 mM glucose from the perfused pancreas were similar to those in control mice. However, at 30 weeks of age, insulin secretion at 30 mM glucose from perfused pancreas in C.C. mice was significantly suppressed compared with that of control mice (p less than 0.02). Conversely, in vivo insulin secretory response to intraperitoneal glucose load was significantly increased in C.C. mice (p less than 0.05). There were no differences in insulin secretion at 15 mM glucose from perfused pancreas. These results indicate that impairment of beta-cell secretory capacity develops in impaired glucose tolerant mice with obesity, while in vivo studies show a high insulin response to glucose. This alteration of beta-cell function may be the initial change during the development of the hyperglycemia-induced defect in insulin secretion.
 ...
PMID:The effects of overeating on insulin secretion in normal mice. 184 Oct 30

The mechanisms underlying different types of obesity have been gradually clarified. Animal models with hypothalamic, genetic or dietary obesity have been examined with a feedback model. Four common final pathways are involved in this model. One of these final common pathways is the sympathetic nervous system. Most Obesities kNown Are Low In Sympathetic Activity states the MONA LISA Hypothesis. A second common pathway is the endocrine system involving adrenal glucocorticosteroids. The third common pathway is hyperphagia. Although not essential for most obesities, hyperphagia may be essential in animals with injury to the hypothalamic paraventricular nucleus. The final pathway is reduced physical activity. The tonic activity of these systems and their response to changes in the diet affect nutrient partitioning between fat and protein. This framework has been used to review genetic obesity, hypothalamic obesity and dietary obesity.
 ...
PMID:Obesity, a disorder of nutrient partitioning: the MONA LISA hypothesis. 186 Nov 65

Lipogenesis was measured in 2 and 5 week gold-thioglucose (GTG) obese mice after a single meal of 0.5 g of standard chow. Compared to control mice the rate of lipogenesis in GTG obese mice, was 4-fold higher in liver and 10-fold higher in white adipose tissue (WAT). In brown adipose tissue (BAT) of GTG-injected mice the lipogenic rate was only 50% of that of controls. These results indicate that the increased lipid synthesis observed in GTG-injected mice is not due solely to hyperphagia and that some other stimuli, such as increased basal insulin levels and/or decreased thermogenesis and insulin resistance in BAT, contribute to the high rates of fat synthesis in this animal model of obesity.
 ...
PMID:Differences in lipogenesis in tissues of control and gold-thioglucose obese mice after an isocaloric meal. 191 74

28 obese women were investigated in the course of the 21st (A) and 30th (B) week of pregnancy. Increased serum levels of GH, T4 and T3 were found in both samples of blood (A and B), while serum insulin, cholesterol and triacylglycerols were increased only at time B. It was suggested that the similar increase of GH, T4 and T3 at time A and B was due to pregnancy because the level of these hormones is usually not increased in non-pregnant obese women, while hyperinsulinemia and often increased values of cholesterol and triacylglycerols are a common finding in non-pregnant obesity. This presumption was confirmed only partially--body weight and the skin folds correlated only with insulin and T3, while GH, cortisol, T4, cholesterol and triacylglycerols correlated only exceptionally. High levels of insulin and T3 may be due to overeating.
 ...
PMID:[Pregnancy and obesity. II. Hormonal and metabolic changes]. 191 57

This study was performed to investigate the consequences of developing obesity on glucose homeostasis in animals showing hyperphagia plus vagal hyperinsulinemia and rats that were normophagic and hyperinsulinemic. Male rats were lesioned in the ventromedial hypothalamus (VMH) and kept either under ad libitum or absolute (oral or intragastrical) pair-feeding conditions for 4 weeks. Hyperphagic rats, as well as normophagic VMH rats, became obese, but only ad lib-fed obese rats displayed glucose intolerance to intravenous (IV) glucose infusions. Orally pair-fed VMH rats also showed normal oral and intragastric glucose tolerance, but in intragastrically fed VMH animals and controls, oral and intragastric glucose tolerance was decreased. These results indicate that (1) obesity as a consequence of VMH lesions is not dependent on hyperphagia, confirming earlier reports, and also independent of the ingestion of bulk meals. (2) beta-cell release of insulin to IV glucose infusion is not sufficient when hyperphagia and vagally mediated hyperinsulinemia coincide, and is therefore dependent on several factors; and (3) oral glucose intolerance develops when preabsorptive reflexes are blunted, irrespective of whether the animals were hyperinsulinemic or not.
 ...
PMID:Hyperinsulinemia and glucose tolerance in obese rats with lesions of the ventromedial hypothalamus: dependence on food intake and route of administration. 194 35

Hypothalamic tissue levels of nine regulatory peptides (bombesin, calcitonin gene-related peptide [CGRP], galanin, neuromedin B, neuropeptide Y [NPY], neurotensin, somatostatin, substance P, and vasoactive intestinal peptide [VIP]) were compared in Aston obese diabetic (ob/ob) and lean (+/?) mice aged 4, 16, and 28 weeks. Neurotensin concentrations were significantly lower in ob/ob mice than in lean mice, with a 20% reduction (P = .03) in the whole hypothalamus at 4 weeks of age, a 24% reduction (P = .009) in the lateral hypothalamus at 16 weeks, and a 50% reduction (P = .0007) in the central hypothalamus at 28 weeks of age. Apart from a 42% increase in vasoactive intestinal peptide concentrations in the central hypothalamus of ob/ob mice at 28 weeks (P = .02), levels of the other eight peptides examined did not differ significantly between obese and lean groups. Neurotensin is known to cause anorexia and increased energy expenditure when injected into the central hypothalamus. Reduced hypothalamic neurotensin concentrations may reflect reduced neurotensinergic activity, which might contribute to hyperphagia and decreased energy expenditure, two major defects that contribute to obesity and diabetes in the ob/ob syndrome.
 ...
PMID:Reduced hypothalamic neurotensin concentrations in the genetically obese diabetic (ob/ob) mouse: possible relationship to obesity. 194 36


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>