TISSUE ENZYME RESPONSE TO COLD AND TO HYPERPHAGIA IN THE RAT

In rats exposed to cold (5C) for 14 days the activities of liver arginase, alanine-transaminase, and glucose-6phosphatase and of kidney phosphate-activated glutaminase were increased. In animals with a comparable hyperphagia due to bilateral ablation of the ventromedial region of the hypothalamus there was a smaller although significant increase in activity of kidney glutaminase but, in contrast to the effect of cold exposure, there was a significant decrease of liver alanine-transaminase activity and no apparent effect upon the activities of liver arginase or glucose-6-phosphatase. It is concluded that changes of enzyme activities in cold-exposed rats are not simply an adaptation to the increased nutrient flow consequent upon the hyperphagia induced. (Author) Pub. in Canadian Journal of Physiology and Pharmacology, v42 p787-91 1964 (Copies available only to DDC users).