Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020505 (hyperphagia)
 6,116 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cocaine and amphetamine-regulated transcript (CART) mRNA and immunoreactivity are expressed abundantly in the hypothalamus. Central administration of various fragments of this neuropeptide decreases food intake in rodents. To find out whether CART might play a role in the physiological regulation of energy balance, we used in situ hybridization to investigate whether CART mRNA abundance changed in two chronic obese/fat versus lean states and after acute dietary restriction. In the first study, mice were treated with goldthioglucose to destroy glucose-responsive neurones in the ventromedial hypothalamus. This produced hyperphagia and obesity: 7 weeks after treatment, those receiving goldthioglucose weighed 70% more than the controls. CART mRNA abundance in the arcuate nucleus of goldthioglucose-treated mice was decreased by 71% compared to levels in the control mice, but CART expression was unaffected in the dorsolateral hypothalamus. In the second study, male Siberian hamsters were exposed to short days to induce a physiological winter response in which body weight decreases as fat reserves are catabolized, and food intake correspondingly declines. After 8 weeks in short days, body weight had declined by 18% relative to controls maintained in long days in a summer fat state. CART mRNA levels did not differ significantly between the two groups in any hypothalamic areas. In the third study, male Siberian hamsters, either in long days or after 12 weeks exposure to short days to induce weight loss, were subject to a 48-h period of fasting. Although photoperiod per se did not affect CART expression, fasting produced a significant decrease in CART mRNA in the arcuate nucleus of hamsters in both the long- and short-day state. We conclude that CART-producing cells are involved in energy homeostasis: the marked decrease in CART expression in the arcuate nucleus in goldthioglucose-lesioned mice may contribute to the development of obesity, and the decrease following acute dietary restriction in hamsters may reflect a compensatory mechanism to reduce caloric expenditure, but our results do not indicate that CART is involved in long-term seasonal regulation of body weight.
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PMID:Cocaine and amphetamine-regulated transcript mRNA regulation in the hypothalamus in lean and obese rodents. 1221 31

Progression of the diabetic trait is usually more rapid in males than females. The major aim of the present study is to explore sexual dimorphism in the hypothalamus in Akita mice. Akita male mice develop hyperphagia, reducing anorexigenic proopiomelanocortin (POMC), and increasing orexigenic neuropeptide Y (NPY) mRNA levels compared with wt males. Serum leptin level was suppressed in Akita males, though castration improved these levels leading to reductions of hyperphagia and blood glucose levels. While Akita female mice also developed hyperphagia, there was no difference in POMC, NPY and leptin levels between Akita and wt females. Anorexigenic Cocaine- and amphetamine-regulated transcript (CART) and corticotrophin-releasing factor (CRF) mRNA levels in Akita females were decreased against wt females. Gonadectomy did not have any effect on the regulation of these neuropeptides. These data suggested that there is sexual dimorphism of neuronal regulation in hyperphagia in Akita mice.
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PMID:Dimorphic gene expression patterns of anorexigenic and orexigenic peptides in hypothalamus account male and female hyperphagia in Akita type 1 diabetic mice. 1714 Nov 81

Cocaine- and amphetamine-regulated transcript (CART) peptide is a neuro-peptide implicated in the regulation of energy homeostasis. CART mRNA and its encoded peptide have been found in many brain regions that regulate energy balance. To investigate the effects of chronic central expression of CART in the diet-induced-obese (DIO) rats, we constructed and packaged recombinant adeno-associated virus (AAV) 2 vector containing rat CART cDNA and a reporter gene encoding green fluorescence protein (AAV-rCART-hrGFP) driven by the CMV promoter. Approximately 1x10(11) particles of AAV-rCART-hrGFP or control vector AAV-IRES-hrGFP (AAV-hrGFP in short) were injected through intracerebroventricular (ICV) cannulas into adult male DIO Long-Evans rats. Throughout the 7-month study period, AAV-rCART-hrGFP-injected rats had a significantly decreased food intake and body weight gain when compared with those of AAV-hrGFP-injected rats. AAV-rCART-hrGFP injection also modulated hyperphagia following a 24-hour fasting in these rats. Body composition analysis indicated that decreased body weight gain was due to reduction in lean body mass while fat mass was not affected. Expression of green fluorescence protein (GFP) suggested that recombinant AAV virions are located at cells surrounding the third ventricle and medial eminence. Our results demonstrate that chronic expression of CART in brain can modulate energy intake in diet-induced-obese rats. The CART pathway plays an important role in body mass regulation in DIO rats.
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PMID:Central CART gene delivery by recombinant AAV vector attenuates body weight gain in diet-induced-obese rats. 1718 22

Previously, 40% food restriction of male Siberian hamsters over 21 days in short-day (SD) photoperiod induced characteristic changes in expression of hypothalamic arcuate nucleus energy balance genes; mRNAs for neuropeptide Y, agouti-related peptide, and leptin receptor were upregulated, and those of proopiomelanocortin and cocaine- and amphetamine-regulated transcript were depressed. The present study examined the effect of refeeding hamsters for 6 days (approximately 50% recovery of weight differential) or 19 days (resumption of appropriate weight trajectory). Hyperphagia continued throughout refeeding, but differences in fat pad weights and leptin levels had disappeared after 19 days. Cocaine- and amphetamine-regulated transcript gene expression was depressed by prior restriction in both refed groups. The depressive effect of prior restriction on proopiomelanocortin gene expression had disappeared after 19 days of refeeding. There was no effect of prior food restriction on neuropeptide Y or agouti-related peptide gene expression. Expression of the anorexigenic brain-derived neurotrophic factor was downregulated in the ventromedial nucleus after SD exposure for 12 wk. In the SD food restriction study, there were effects of photoperiod on brain-derived neurotrophic factor gene expression but not of prior food restriction. Hypothalamic energy balance genes in the hamster respond asynchronously to return to a seasonally appropriate body weight. The achievement of this weight rather than the weight at which caloric restriction was imposed is the critical factor. The differential responses of hypothalamic energy balance genes to food restriction and refeeding are poorly characterized in any species, a critical issue given their potential relevance to human weight loss strategies that involve caloric restriction.
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PMID:Hypothalamic neuropeptide gene expression during recovery from food restriction superimposed on short-day photoperiod-induced weight loss in the Siberian hamster. 1759 23

Ghrelin and GH secretagogues, including GH-releasing peptide (GHRP)-6, stimulate food intake and adiposity. Because insulin modulates the hypothalamic response to GH secretagogues and acts synergistically with ghrelin on lipogenesis in vitro, we analyzed whether insulin plays a role in the metabolic effects of GHRP-6 in vivo. Streptozotocin-induced diabetic rats received saline, GHRP-6, insulin, or insulin plus GHRP-6 once daily for 8 wk. Rats receiving saline suffered hyperglycemia, hyperphagia, polydipsia, and weight loss. Insulin, but not GHRP-6, improved these parameters (P < 0.001 for all), as well as the diabetes-induced increase in hypothalamic mRNA levels of neuropeptide Y and agouti-related peptide and decrease in proopiomelanocortin. Cocaine amphetamine-related transcript mRNA levels were also reduced in diabetic rats, with GHRP-6 inducing a further decrease (P < 0.03) and insulin an increase. Diabetic rats receiving insulin plus GHRP-6 gained more weight and had increased epididymal fat mass and serum leptin levels compared with all other groups (P < 0.001). In epididymal adipose tissue, diabetic rats injected with saline had smaller adipocytes (P < 0.001), decreased fatty acid synthase (FAS; P < 0.001), and glucose transporter-4 (P < 0.001) and increased hormone sensitive lipase (P < 0.001) and proliferator-activated receptor-gamma mRNA levels (P < 0.01). Insulin normalized these parameters to control values. GHRP-6 treatment increased FAS and glucose transporter-4 gene expression and potentiated insulin's effect on epididymal fat mass, adipocyte size (P < 0.001), FAS (P < 0.001), and glucose transporter-4 (P < 0.05). In conclusion, GHRP-6 and insulin exert an additive effect on weight gain and visceral fat mass accrual in diabetic rats, indicating that some of GHRP-6's metabolic effects depend on the insulin/glucose status.
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PMID:The positive effects of growth hormone-releasing peptide-6 on weight gain and fat mass accrual depend on the insulin/glucose status. 2021 77