Adenosine 3',5'-cyclic monophosphate and enzyme induction in the perinatal rat.

Adenosine 3’,5’-cyclic monophosphate (cyclic AMP) is recognized to be the intracellular mediator of several hormones [ 11. In the perinatal rat, cyclic AMP has been implicated in the control of synthesis of hepatic tyrosine aminotransferase and phosphopyruvate carboxylase [2-51. Results from this laboratory suggest that the induction of the two enzymes is triggered by an increase in the intracellular concentration of cyclic AMP [S]. Increases in cyclic AMP concentration in the liver during the perinatal period have been demonstrated [S-7] which preceded or were coincident with the increases in the activities of the two enzymes [5,7-91. In addition, it appears that a critical concentration of cylic AMP must be reached for effects on enzyme synthesis to occur [S]. In this report we present evidence of a positive significant correlation between the cyclic AMP concentration and the activity of tyrosine aminotransferase and phosphopyruvate carboxylase in the livers of newborn rats. The results support the hypothesis that cylic AMPis an important factor in the induction of the two enzymes in the perinatal rat in vivo.