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

The present study was undertaken to clarify the mechanism of the diabetogenic activity of streptozotocin. Experiments were conducted to determine the resistance of animals to the diabetogenic action of streptozotocin; to follow the time course of irreversible beta-cell damage, and to determine the influence on streptozotocin action of certain compounds. Streptozotocin, a broad spectrum antibiotic, with antitumoral properties, was shown to be diabetogenic in rats and mice, but not in cats, rabbits, or guinea pigs. Intravenous or intraperitoneal administration of 65 mg/kg body weight of streptozotocin to male Wistar rats evoked a tri-phasic blood sugar response. It induced an initial hyperglycemic peak with no apparent change in plasma insulin concentrations, followed by profound hypoglycemia caused by liberation of large amounts of insulin from the pancreas. Forty-eight hours after injection, the animals were completely diabetic. Light- and electron-microscopic exadminations during the first forty-eight hours after the injection of streptozotocin showed pyknosis, degranulation and marked degeneration of the beta-cells. 1egenerative and necrotic changes were also seen in a few alpha-cells. These streptozotocin-induced diabetic rats revealed polydipsia, polyuria, polyphagia and glucosuria, and decreased body weight. Blood sugar, plasma FFA and insulin concentrations were examined after oral administration of glucose (OGTT: 3g/kg). Blood sugar and plasma FFA were significantly elevated but plasma insulin concentrations were markedly decreased, so insulin treatments were most effective in these animals. It has been reported that nicotinamide prevents the diabetogenic activity of streptozotocin and the deformity action of 6-aminonicotinamide and 3-acetylpridine. Pre-treatment with picolinamide, methyl-nicotinamide, and nicotinohydroxamic acid also blocked its diabetogenic action, but nicotinic acid, mannoheptulose and glucose were ineffective. N-nitrosodimethylamin and ethyl-N-nitrosomethylcarbamate were devoid of diabetogenicity. It seems that streptozotocin interfers with NAD formation in the beta-cell. Functioning pancreatic islets cell tumors were observed on the rats both at 407 days after streptozotocin administration and at 473 days after streptozotocin administration with nicotinamide (500 mg/kg, i.p.).
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PMID:[Studies on the mechanism of the diabetogenic activity of streptozotocin and on the ability of compounds to block the diabetogenic activity of streptozotocin (author's transl)]. 16 68

The metabolic effect of ventromedial hypothalamic (VMH) lesions, which are known to cause hyperphagia and obesity, has been studied in rats kept on a controlled light and food regimen. The animals were sacrificed at 4 different times during the second postoperative day. A feeding-induced hypersecretion of insulin was found to the VMH-lesioned animals. It was accompanied by a marked hypoglycemia as compared to the control groups during the feeding period. The glycogen content of liver and diaphragm in the lesioned groups is increased as compared to the controls during the same period. The VMH-lesioned animals showed hypertriglyceridemia both in the fed and fasted state, whereas the postabsorptive plasma levels of free fatty acids and glycerol were decreased. An increased level of urea was observed in all lesioned groups. This is in accordance with the demonstrated protein catabolism which follows VMH lesions.
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PMID:The effect of ventromedial hypothalamic lesions on metabolism and insulin secretion in rats on a controlled feeding regimen. 102 15

Parasagittal knife cuts through the perifornical hypothalamus either medial or lateral to the fornix produced hyperphagia and obesity and altered the rat's ingestive responses to dilute glucose solutions. The lateral knife cut rats drank less dilute glucose solution under both nondeprived and food deprived conditions and displayed less of a feeding suppressive response to glucose ingestion compared to controls. The lateral cut rats were also deficient in their feeding response to insulin-induced hypoglycemia, although their altered sensitivity to glucose and insulin did not appear to be causally related. The medial knife cuts decreased the responsivity to glucose, but less so than the lateral cuts, and did not alter the ingestive response to insulin. Both the medial and lateral knife cuts did not appear to change the rat's responsivity to concentrated blucose solutions. The neuroanatomical and functional nature of the disorder responsible for these effects and its relationship to the hyper-phagia-obesity syndrome are discussed.
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PMID:Effects of hypothalamic knife cuts on the ingestive responses to glucose and insulin. 119

Somatostatin, gastrin-releasing peptide (GRP) and gastrin were measured in the stomach of rats with streptozotocin-induced diabetes, insulinoma-bearing rats and their respective controls. Rats injected with streptozotocin exhibited hyperphagia, insulinopenia and severe hyperglycemia. Stomach weights, and the concentrations and total amounts of GRP and gastrin in the stomach, were similar to nondiabetic control rats. The concentration of somatostatin in the stomach of diabetic rats was 25% greater, but the total stomach content of somatostatin was similar to that of control rats. Insulinoma-bearing rats exhibited hyperphagia, hyperinsulinemia and hypoglycemia. Concentrations of GRP and gastrin in the stomach were 72% and 19% lower, respectively, than in control rats. Despite 45% greater stomach weight, the total stomach content of GRP was 61% lower. Stomach concentrations of somatostatin, and total stomach contents of somatostatin and gastrin, were similar in insulinoma-bearing and control rats. The results demonstrate abnormalities in the stomach concentrations of regulatory peptides in rats with diabetes and insulinoma. These abnormalities are not attributable to changes in food intake alone, suggesting specific effects of these metabolic diseases on gastric regulatory peptides and gastric function.
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PMID:Somatostatin, gastrin-releasing peptide and gastrin in the stomach of rats with streptozotocin-induced diabetes and insulinoma. 167 27

Hypothalamic concentrations of neuropeptide Y (NPY), a potent central appetite stimulant, increase dramatically in food-restricted and insulin-deficient diabetic rats. This suggest that NPY may drive hyperphagia in these conditions, which are characterized by weight loss and insulin deficiency. To test the hypothesis that insulin deficiency and weight loss are specific stimuli to hypothalamic NPY, we measured NPY concentrations in individual hypothalamic regions in rats with hyperphagia caused by insulin-induced hypoglycemia. Groups of 8 male Wistar rats were injected with ultralente insulin (20-60 U/kg) to induce either acute hypoglycemia (7 h after a single injection) or chronic hypoglycemia (8 days with daily injections). In hypoglycemic rats, plasma insulin concentrations were increased 6- to 7-fold compared with saline-injected controls; food intake was significantly increased with acute and chronic hypoglycemia and weight gain was significantly increased in the chronically hypoglycemic group. NPY concentrations were measured by radioimmunoassay in 8 hypothalamic regions microdissected from fresh brain slices. NPY concentrations were not increased in any region in either acute or chronic hypoglycemia. NPY therefore seems unlikely to mediate hyperphagia in hyperinsulinemia-induced hypoglycemia, supporting the hypothesis that weight loss is a specific stimulus to hypothalamic NPY and that insulin deficiency may be the metabolic signal responsible.
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PMID:Unchanged hypothalamic neuropeptide Y concentrations in hyperphagic, hypoglycemic rats: evidence for specific metabolic regulation of hypothalamic NPY. 192 23

Insulin levels in a 7-year-old boy with hyperphagia and obesity following an episode of meningoencephalitis were studied sequentially during the course of progressive weight gain. High fasting insulin levels (1183 pmol/L) and strikingly high insulin release in response to glucose (7892 pmol/L) were found within weeks of the onset of the illness. The abnormality in insulin secretion occurred prior to the marked weight gain. Hyperinsulinemia was not accompanied by hypoglycemia. Early hyperinsulinemia may be a primary event in the development of hyperphagia and obesity following hypothalamic injury.
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PMID:Hypothalamic or central obesity is associated with an early rise in plasma insulin concentration. 201 20

The clinical pattern of the chronic hypoglycemic disorders is different from that of the acute disorders. While in acute hypoglycemic syndromes tachycardia usually occurs, in chronic hypoglycemic disorders there is, even if seldom, sinusal bradycardia. The bradycardia occurs after months with glycemia under 60 mg/dl and may be correlated to the neuroglycopenic state. It is easily reversible when plasma glucose concentration approaches the normal range again. Recently we observed sinusal bradycardia set up during the chronic hypoglycemia state, lasting from more than 5 months, in a man submitted to subtotal intestinal resection, owing to wide extensive eosinophilic granuloma. The bradycardia disappeared quickly after the correction of the hypoglycemia, when the patient was submitted to parenteral hyperalimentation with a silicone rubber catheter in the superior vena cava. We suggest to set the bradycardia among the markers of undernutritional syndromes beside the known anthropometric, biochemical and immunological signs.
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PMID:[Sinus bradycardia in chronic neuroglycopenic syndrome. A case of "short intestine" syndrome]. 251 64

Twelve plants used for the traditional treatment of diabetes mellitus in northern Europe were studied using normal and streptozotocin diabetic mice to evaluate effects on glucose homeostasis. The plants were administered in the diet (6.25% by weight) and/or as decoctions or infusions in place of drinking water, to coincide with the traditional method of preparation. Treatment for 28 days with preparations of burdock (Arctium lappa), cashew (Anacardium occidentale), dandelion (Taraxacum officinale), elder (Sambucus nigra), fenugreek (Trigonella foenum-graecum), guayusa (Ilex guayusa), hop (Humulus lupulus), nettle (Urtica dioica), cultivated mushroom (Agaricus bisporus), periwinkle (Catharanthus roseus), sage (Salvia officinale), and wild carrot (Daucus carrota) did not affect the parameters of glucose homeostasis examined in normal mice (basal plasma glucose and insulin, glucose tolerance, insulin-induced hypoglycaemia and glycated haemoglobin). After administration of streptozotocin (200 mg/kg) burdock and nettle aggravated the diabetic condition, while cashew, dandelion, elder, fenugreek, hop, periwinkle, sage and wild carrot did not significantly affect the parameters of glucose homeostasis studied (basal glucose and insulin, insulin-induced hypoglycaemia, glycated haemoglobin and pancreatic insulin concentration). Guayusa and mushroom retarded the development of hyperglycaemia in streptozotocin diabetes and reduced the hyperphagia, polydipsia, body weight loss, and glycated haemoglobin. Mushroom also countered the initial reduction in plasma insulin and the reduction in pancreatic insulin concentration, and improved the hypoglycaemic effect of exogenous insulin. These studies suggest the presence of potentially useful antidiabetic agents in guayusa and mushroom.
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PMID:Glycaemic effects of traditional European plant treatments for diabetes. Studies in normal and streptozotocin diabetic mice. 274 11

Metabolic effects of 3 different sites of transplantation of cultured tumour cells from a radiation induced insulinoma (28 X 10(6) viable cells per rat) were examined in 15-18 weeks old male NEDH rats. Subscapular implantation consistently produced a highly vascularised encapsulated tumour associated with hyperinsulinaemia, hyperphagia and hypoglycaemia by 21 days, which progressed to fatal neuroglycopaenic coma at 37 +/- 3 days (mean +/- SEM). Implantation of tumour cells into the hepatic portal vein resulted in a multilobular hepatic tumour in two out of nine rats, with hyperinsulinaemia and fatal hypoglycaemia by 49-54 days. Irregularities of glucose homeostasis were observed in a further three rats by 62 days. Intrapancreatic implantation consistently produced a similar tumour to that observed at the subscapular site. Implantation into the pancreas produced the most rapid onset of hyperinsulinaemia, hyperphagia and hypoglycaemia, with survival for only 28 +/- 3 days. The results demonstrate an important effect of transplantation site on the function and metabolic consequences of the NEDH rat insulinoma.
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PMID:Metabolic effects of radiation induced rat insulinoma at pancreatic, hepatic and subscapular transplantation sites. 287 15

The metabolic effects and secretory properties of a radiation-induced transplantable insulinoma were examined in 16-17 week old NEDH rats. Subcutaneous subscapular implantation of tumour fragments resulted in hyperphagia, increased body weight gain, marked hyperinsulinaemia and severe hypoglycaemia, with the resulting death of the recipient by 27 days. Ultimate tumour size was 2.1 +/- 0.4 g (mean +/- SEM). At 3 days after transplantation, plasma glucose and insulin responses to intraperitoneal glucose, insulin, arginine and adrenaline were similar to control rats. At 20 days, plasma glucose concentrations of insulinoma-bearing rats remained low throughout glucose tolerance tests, and insulin responsiveness to glucose stimulation was absent. 2-Deoxy-D-glucose produced only a small rise of glucose concentrations in tumour-bearing rats. Insulin sensitivity was not appreciably impaired at 20 days despite severe hyperinsulinaemia and hypoglycaemia. The ability of adrenaline and propranolol to suppress plasma insulin and raise plasma glucose concentrations was also retained. At 20 days, glucagon evoked a marked plasma insulin response with no change in plasma glucose concentrations. In contrast, arginine and glibenclamide failed to stimulate insulin above high basal concentrations.
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PMID:Metabolic effects and secretory properties of a radiation-induced transplantable rat insulinoma. 288 53


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