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Query: UMLS:C0020672 (hypothermia)
 17,327 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cooling of rats down to the rectal temperature of 33--35 degrees without the use of narcotic and neuroplegic drugs did not cause distinct alterations in activity of the oxidative enzymes of tricarboxylic acid cycle--isocitrate dehydrogenase, alpha-ketoglutarate dehydrogenase, malate-, succinate- and pyruvate dehydrogenases in brain tissue. At the same time, inhibition of the activity of these dehydrogenases occurred in profound hypothermia (cooling to 19--20 degrees). In this case the activity of succinate dehydrogenase was decreased less distinctly as compared with the activity of NAD-dependent dehydrogenases. Succinic acid appears to be an especially important substrate for oxidation in brain of the chilled rats.
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PMID:[Activity of Krebs cycle oxidative enzymes in the brain in hypothermia]. 45 97

During short-lasting hypothermia in rats the activity of isocitrate dehydrogenase (E.C.1.1.1.42) and malic dehydrogenase (E.C.1.1.1.37) was determined in the mitochondrial fraction of liver cells, myocardial cells and skeletal muscle fibres of the femoral muscle and no statistically significant differences were found between the obtained values and those in a control group. On the other hand, the activity of glucose-6-phosphate dehydrogenase (E.C.1.1.1.49) in the cytoplasmic fraction of these tissues was decreased in the hypothermic rats by 46% in the liver, by 50% in the myocardium and by 59% in the skeletal muscle of the thigh. A possible cause of this reduced activity of this enzyme in hypothermia could be changes in the structure of the enzymatic protein, deficiency of the hormone activating the enzyme, that is insulin, and/or inhibition of the pentose-phosphate cycle by fatty acids released in excess.
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PMID:Activity of certain enzymes in the mitochondrial and cytoplasmic fractions of liver cells, myocardium and skeletal muscle of the rat during short-lasting hypothermia. 718 57

As shown in our previous study, hypothermia provokes a variety of hormonal changes including inhibition of insulin secretion and increase in blood serum glucagon level. According to Therminarias et al. the administration of exogenous insulin to dogs subjected to hypothermia causes a calorigenic effect by enhancing oxygen consumption and rising the intensity of shivering thermogenesis. The study was aimed at establishing whether exogenous insulin administered to rats subjected to brief hypothermia and having the shivering thermogenesis blocked by thiobutabarbital anesthesia can influence rectal temperature, the levels of some hormones and energy metabolism. The results obtained suggest that 1) insulin administration causes an increase in the energy charge potential (ECP) both in the liver and in skeletal muscle of the rat, indicating the domination of anabolic processes both in normothermic and hypothermic conditions, 2) there is a negative correlation between the levels of insulin and free fatty acids and the activity of isocitric dehydrogenase in rat liver mitochondria, and 3) the administration of insulin at a dose provoking metabolic response both in normothermic and hypothermic conditions was ineffective in provoking temperature response, indicating the existence of a functional dissociation between the various effects of the same dose of exogenous insulin.
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PMID:[Effect of insulin on temperature and metabolic responses in rats during normothermia and hypothermia]. 805 Mar 87