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Query: UMLS:C0020505 (hyperphagia)
 6,116 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study was undertaken to determine whether a reduction in body weight in laboratory mice by regimens that appear to delay the rate of aging (i.e., food restriction and chronic dehydroepiandrosterone (DHEA) treatment), or a production of obesity by the presence of the ob (obese) gene or by gold thioglucose-induced hyperphagia alter the rate of binding of 3H-7,12-dimethylbenz(a)anthracene (3H-DMBA) to mouse skin deoxyribonucleic acid (DNA). We have found that treating A/J mice with food containing .6% DHEA for 10 weeks or reducing the food intake of non-DHEA treated mice to 60% of ad libitum fed animals significantly reduces the amount of 3H-DMBA bound to mouse skin DNA 12 hours after a topical application of the carcinogen. Conversely, A/J mice made obese by a gold thioglucose-induced hyperphagia and C57BL/6J mice with the ob mutation bind significantly increased amounts of 3H-DMBA to skin DNA when compared to their nonobese counterparts.
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PMID:Effect of food restriction, dehydroepiandrosterone, or obesity on the binding of 3H-7,12-dimethylbenz(a)anthracene to mouse skin DNA. 621 39

Obesity is typically associated with increased tumor susceptibility, whereas caloric restriction, a regimen resulting in leanness, inhibits carcinogenesis. The link between adiposity and malignancies suggests that adipose tissue may influence carcinogenesis. An adipose tissue hormone, leptin, could be procarcinogenic because it stimulates proliferation in various tissues and tumor cell lines. Leptin may contribute to the correlation between adiposity and malignancies as its levels are usually increased in obese subjects and reduced by caloric restriction. We hypothesized that leptin deficiency, despite obesity, would inhibit carcinogenesis in leptin-null ob/ob mice and tested this hypothesis in two models: (a) two-stage skin carcinogenesis initiated by 7,12-dimethylbenz(a)anthracene and promoted by phorbol 12-myristate 13-acetate (PMA) and (b) p53 deficiency. Contrary to a typical association between obesity and enhanced carcinogenesis, obese ob/ob mice developed induced skin papillomas and spontaneous p53-deficient malignancies, mostly lymphomas, similarly to their lean littermates. Surprisingly, lipodystrophic (ZIP) mice that had very little both adipose tissue and leptin were highly susceptible to carcinogenesis. Hyperphagia, hyperinsulinemia, and hyperglycemia are unlikely to have contributed significantly to the enhancement of carcinogenesis in ZIP mice because similarly hyperphagic, hyperinsulinemic, and hyperglycemic ob/ob mice had normal susceptibility to carcinogenesis. Our data suggest that, in contrast to a well-known correlation between obesity and cancer, the direct effect of adipose tissue may rather be protective.
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PMID:Susceptibility to induced and spontaneous carcinogenesis is increased in fatless A-ZIP/F-1 but not in obese ob/ob mice. 1695 Dec 7

Many studies, both national and international, have shown that tea has protective effects on many chronic diseases and their risk factors. In cancer prevention, our studies indicated that tea drinking could inhibit the carcinogenicity of various chemical carcinogens, including oral tumors induced by 7,12-dimethylbenz[a]anthracene (DMBA) in Golden hamsters, esophageal tumors in rats by blocking in vivo synthesis of N-Nitroso-methylbenzylamine (NMBzA), esophageal cancer induced by NMBzA in rats, precancerous liver lesions (r-GT and GST-P) induced by diethylnitrosamine (DENA) in rats, intestinal preneoplastic lesion (ACF) and intestinal tumors induced by 1,2-dimethyl-hydrazine (DMH) in rats, lung carcinoma induced by nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone(NNK) in A/J mice. Our studies have also shown that the protective effects of tea against cancer is a combined effects of various tea ingredients, among which the major ones are polyphenols and tea pigments. Based on animal studies, antioxidant properties, protection against DNA damage and modulation of immune functions were found to be the main mechanisms of anticancer effects of tea. In human trials, tea drinking showed protective effects against oxidative damage and DNA damage caused by cigarette smoking. Mixed tea drinking significantly blocked lesion progress in patients with oral mucosa leukoplakia, therefore, demonstrated its protective effects on oral cancer. Our studies have also shown effects of tea on prevention of cardiovascular diseases (CVD). For example, tea pigments was found to significantly inhibit LDL oxidation induced by Cu2+, Fe2+ in in vitro studies. In vivo studies showed that tea could prevent blood coagulation, facilitate fibrinogen dissolution, inhibit platelet aggregation, lower endothelin levels, enhance GSH-Px activities, protect against oxidated LDL-induced damage in endothelium cells, and prevent atherosclerosis of coronary arteries. The mechanisms of these protective effects of tea are possibly related to its antioxidant properties or its inhibition of lipid oxidation. Green tea and pigments was also found to inhibit cardiac hypertrophy induced by renal hypertension in rat models, whose mechanisms might, at least partly, involve its modulation on nitric oxide, angiotensin II and endothelin-1. Clinical intervention trials have indicated that tea and tea extracts decreased blood lipid, improved blood flow of coronary artery, and played an important role in atherosis inhibition and prevention. Our studies also showed that tea drinking has protective effects on diabetes. White tea drinking could significantly relieve symptoms including polyuria, polydipsia, polyphagia and weight loss in diabetic mice, decrease fasting plasma glucose level and improve glucose tolerance. In human trial, continuous white tea drinking could significantly improve symptoms of diabetic patients, such as relieve polydipsia, decrease plasma glucose levels, both fasting and 2 hours after meal, and increase insulin secretion. The effective rate for glucose lowering is 48% in clinical study.
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PMID:[Studies on tea and health]. 2227 81