Enzyme response to contractile activity in isolated smooth muscle: effects of cycloheximide and insulin

Abstract 1. 1. The effects of contractile activity on the activities of various enzymes were studied in the isolated smooth muscle taenia coli from the guinea-pig m response to administration of cydoheximide and insulin. ' 2. 2. The muscles were stimulated to contractile activity by carbachol. 3. 3. The activities of pyruvate kinase and cytochrome oxidase were increased. The other enzymes investigated were not significantly affected. 4. 4. Insulin did not influence the enzyme activities in response to contractile activity. 5. 5. Underlying the increase m enzyme activities is probably an increased synthesis of new enzyme protein, as cyclohcximide prevented the increase in enzyme activities.