Long-term starvation in Xenopus laevis Daudin--III. Effects on enzymes in several tissues.

1. Adult, female Xenopus laevis were subjected to 12 months of starvation. 2. Starvation resulted in a continuous reduction in the activity of both hepatic and renal glucose-6-phosphate dehydrogenase. 3. Fructose-1,6-diphosphatase was significantly reduced at months 10 and 12 in the liver, and at months 4, 10, and 12 in the kidney. 4. Pyruvate kinase activity of muscle and liver decreased during the experimental period whereas the renal enzyme remained essentially unchanged. 5. Both hepatic and renal glutamate-pyruvate transaminase (GPT) and hepatic glutamate-oxaloacetate transaminase (GOT) showed a reduction of activity after 2 and 4 months of starvation followed by an increase in GPT but not in GOT.