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)

Nicotine (NIC) and its withdrawal modify dorsal raphe (DR) serotonin (5-HT) neurotransmission in ways that may contribute to the body weight loss vs. gain associated with cigarette smoking vs. cessation, respectively. Modifications in feeding to DR infusions of the 5-HT-1A receptor agonist, 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT), were used to characterize these potential relationships in the DR-5-HT system during NIC administration vs. withdrawal. Two groups of female rats (total N=45) were implanted for 14 days with subcutaneous Alzet minipumps containing NIC (6 mg/kg/day) or saline. Mid-light cycle (1300-1500 h) 8-OH-DPAT feeding tests occurred three times: (1) 2 days after pump implant, (2) 12 days after pump implant, and (3) 2 days after pump removal. Each feeding test consisted of a 1-h measure of pre-feeding, then a 1-h measure of feeding after DR injection of 8-OH-DPAT (0.6 nmol) or 0.4 microl saline. NIC administration produced acute hypophagia, weight loss, and attenuated 8-OH-DPAT-induced feeding. NIC withdrawal produced acute hyperphagia, weight gain, and a transient increase in 8-OH-DPAT feeding. These findings provide behavioral evidence that systemic NIC modifies the DR 5-HT system in ways that may contribute to NIC's ability to alter feeding and body weight.
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PMID:Nicotine and its withdrawal modify dorsal raphe 8-hydroxy-2-(di-n-propylamino) tetralin feeding. 1266 11

In view of an effect of high intake of sugar on brain serotonin (5-hydroxytryptamine, 5-HT) and a role of serotonin in the regulation of appetite, the present study concerns pre and postsynaptic responses to a selective 5-HT-1A receptor agonist 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT) following long term consumption of sugar as part of meal in rats. Sugar diet was prepared by mixing standard rodent diet and table sugar in ratio of 3:1 (w/w) and rats were fed freely on this diet for five weeks. Control rats were fed freely on standard rodent diet. After five weeks 8-OH-DPAT at a dose of 0.5mg/kg/ml was injected to both the groups to compare effectiveness of the drug to elicit hyperphagia (presynaptic response) and elicited hyperactivity syndrome (postsynaptic response). Results showed that 8-OH-DPAT-induced forepaw treading and flatbody posture were smaller in sugar than normal diet treated rats. Conversely 8-OH-DPAT-induced hyperlocomotion was greater in sugar than normal diet treated rats. 4h Food consumption was greater in sugar than normal diet treated rats while 8-OH-DPAT-induced hyperphagia significant in normal diet treated rats was not observed in sugar diet treated rats. The results show a decrease in the effectiveness of pre as well as postsynaptic 5-HT-1A receptor dependent responses following long term consumption of sugar diet. Role of serotonin receptor responsiveness on mood and impaired adaptation to stress is discussed.
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PMID:Effects of long term consumption of sugar as part of meal on serotonin 1-a receptor dependent responses. 1675 Nov 17

8-Hydroxy-2-(di-n-propylamino)-tetralin (8-OH-DPAT), a 5-hydroxytryptamine (5-HT)-1A selective agonist was used to investigate a possible role of somatodendritic serotonin-1A receptors in the precipitation of hyperphagia and decreases of 5-HT metabolism associated with long-term consumption of sugar rich-diet. In the first part of study, dose-related hyperphagic effects of 8-OH-DPAT were monitored in freely feeding rats. In the second part of study, rats were fed freely on a sugar-rich diet (prepared by mixing standard rodent diet with table sugar in the ratio of 3:1 [w/w]) for 5 weeks. Hyperphagic effects of 8-OH-DPAT were monitored in sugar-rich diet and normal diet treated rats by injecting the drug at a dose of 0.25 mg/kg body weight, a dose that produced significant hyperphagia. Effects of 8-OH-DPAT on decreasing 5-HT metabolism in the hypothalamus were also investigated in the two groups. Results showed that administration of 8-OH-DPAT at a dose of 0.25 mg/kg body weight elicited hyperphagia and decreased 5-HT metabolism in normal diet treated animals but the effects in sugar-rich diet treated animals were smaller and not significant suggesting a decrease in the effectiveness of somatodendritic 5-HT-1A receptors, which provide a feedback control over the synthesis and release of 5-HT in terminal region. A possible mechanism involved in sugar-diet induced decreases of 5-HT metabolism is discussed.
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PMID:Long-term consumption of sugar-rich diet decreases the effectiveness of somatodendritic serotonin-1A receptors. 1900 Mar 81