Effects of insulin and beta-adrenergic blockade on certain indicators of carbohydrate metabolism in the blood and tissues of rats during short-lasting hypothermia.
Administration of insulin 1 i.u./100 g of body weight to hypothermic rats causes a fall of glucose and lactate levels in the serum and a rise in myocardial glycogen level in relation to the group of control rats kept at room temperature and to the group of rats subjected only to hypothermia. Beta-adrenergic blockade (propranolol 0.6-1 mg/kg) caused no changes in the levels of carbohydrate metabolites in the serum of hypothermic rats but raised the myocardial glycogen level by 42% in relation to the animals subjected only to hypothermia. Simultaneous administration of both these agents during hypothermia produces a fall of the serum levels of glucose and pyruvate with a rise in the level of lactate, and raises the glycogen level in the myocardium (by about 161%) and in the skeletal muscle (by 54%) in relation to the rats subjected to hypothermia alone. Insulin and/or propranolol fail to prevent glycogen reserve exhaustion in the liver of hypothermic rats which could be due to activation of non-blocked alpha-adrenergic receptors or to the action of yet another glycogenolytic agent, e.g. glucagon, during hypothermia.
D000208:Acute Disease; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D050260:Carbohydrate Metabolism; D006003:Glycogen / Q000032:analysis; D007035:Hypothermia / Q000097:blood* / Q000378:metabolism; D007328:Insulin / Q000494:pharmacology*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains
D000319:Adrenergic beta-Antagonists; D007328:Insulin; D006003:Glycogen