Effect of protein kinase C on amylase secretion and cyclic AMP production in rat pancreatic acinar cells.
The authors examined the effects of protein kinase C on secretin-induced amylase release and cyclic AMP production in rat pancreatic acinar cells. Secretin (10(-6) M) and 12-O-tetradecanoyl-phorbol 13-acetate (TPA) (10(-6) M) induced 53% and 60% increase of amylase release from the basal level, respectively during 10 min. Simultaneous addition of TPA and secretin resulted in 42% amylase release from the basal level for 10 min. Suppression of secretin-induced amylase release was evident within 5 min of pretreatment with TPA. TPA showed the same effect on cyclic AMP production; secretin-induced increase of cyclic AMP was suppressed by pretreatment of TPA for 5 min. To explore the mechanism by which TPA inhibits secretin-induced cyclic AMP production, we also examined the effects of protein kinase C purified from rat brain on adenylate cyclase activity in pancreatic acinar membranes. Basal, forskolin- and secretin plus guanosine 5'-[gamma-thio]trisphosphate-stimulated adenylate cyclase activity were inhibited by protein kinase C in the presence of Ca++. These results suggest that protein kinase C might have a role in the inhibitory effect on adenylate cyclase in exocrine pancreas.
Ishizuka
T
T
Third Department of Internal Medicine, Gifu University School of Medicine, Japan.
Ito
Y
Y
Miura
K
K
Nagao
S
S
Nozawa
Y
Y
D000067956:Adenylyl Cyclase Inhibitors; D000681:Amylases / Q000378:metabolism*; D000818:Animals; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000096:biosynthesis*; D008297:Male; D010179:Pancreas / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D011493:Protein Kinase C / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D012633:Secretin / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D000067956:Adenylyl Cyclase Inhibitors; D012633:Secretin; D000242:Cyclic AMP; D011493:Protein Kinase C; D000681:Amylases; D013755:Tetradecanoylphorbol Acetate