AMINO-ACID-METABOLISM ENZYME-ACTIVITIES IN THE OBESE ZUCKER RAT

Hepatic serine dehydratase activity was significantly lower in the obe se Zucker rats. In both skeletal muscle and kidney adenylate deaminase showed a lower activity in the obese animals. In the small intestine the activity of glutamate dehydrogenase was increased while that of gl utamine synthetase was reduced. No changes were found in the enzymatic activities of white adipose tissue while those found in brown adipose tissue were lower for glutamine synthetase. Starvation resulted in in crease in liver serine dehydratase in the lean animals and in aspartat e transaminase in both lean and obese. Kidney aspartate transaminase a nd glutamine synthetase were increased with starvation in the lean rat s while kidney adenylate deaminase and small intestine glutamine synth etase and branched-chain amino acid transaminase were increased with s tarvation in the obese animals. In brown adipose tissue starvation cau sed an increase in branched-chain amino acid transaminase in the lean rats while it significantly lowered the adenylate deaminase and increa sed branched-chain amino acid transaminase in the obese rats.