Effects of Glucagon, Phosphodiesterase Inhibitors, and Trypsin Treatment on Cyclic 3',5' Adenosine Monophosphate Levels in Isolated Hepatocytes[*]

Abstract

Cyclic 3',5' adenosine monophosphate (cyclic AMP) levels were measured in isolated hepatocytes under several conditions. Following the addition of glucagon cyclic AMP levels increased rapidly with peak values occurring at three minutes. The increase in cyclic AMP was dose dependent. Significant increases were found with 10^-10M glucagon and a maximum increase of twenty fold was produced by 10^-8M glucagon. This action of glucagon was augmented by the phosphodiesterase inhibitors, theophylline, SQ 20,009, and papaverine. Treatment of the hepatocytes with trypsin markedly reduced the response to glucagon.

Hepatocytes - Cyclic AMP - Glucagon - Trypsin - Phosphodiesterase Inhibitors

1 This work was supported by United States Public Health Service Grant AM-14070.

2 Recipient of Meade-Johnson Fellowship. Present address: Department of Biochemistry, St. Louis University School of Medicine, St. Louis, Missouri 63104.

3 Recipient of United States Public Health Service Career Development Award 1 KO4-AM-50316.