Transforming growth factor beta 1 increases the phosphoenolpyruvate carboxykinase mRNA level in cultured rat hepatocytes.

Transforming growth factor beta 1 (TGF beta 1) elevated the phosphoenolpyruvate carboxykinase (PEPCK) mRNA abundance in primary cultures of rat hepatocytes. Although this increase was not as large as the rise in PEPCK gene expression induced by the cAMP-elevating agents glucagon or isoproterenol, the effect of TGF beta 1 was several-fold and concentration-dependent, with ED50 at about 2.5 pM, which is in the same concentration range as the previously found growth-inhibitory effect of TGF beta. The data show that the level of mRNA for PEPCK, an enzyme typically expressed in the liver, can be regulated in the same direction by TGF beta 1 and cAMP.