Protein kinase A modulates Ca(2+)- and protein kinase C-dependent amylase release in permeabilized rat pancreatic acini.
The role of protein kinase A (PKA) in the release of amylase from permeabilized pancreatic acini was investigated. Addition of cyclic AMP (cAMP) to permeabilized acini resulted in a potentiation of Ca(2+)-dependent amylase release, shifting the Ca2+ dose/response curve leftwards. As with protein kinase C (PKC) activation, this is due to an increase in the time of active discharge. The effect of cAMP was shown to be blocked by two inhibitors of PKA, H89 and the PKI-(5-24)-peptide. At low concentration, cAMP synergizes from phorbol 12-myristate 13-acetate (PMA), while at optimal concentrations cAMP and PMA are additive. PKA and PKC appear to work via similar, but not identical mechanisms.
D000681:Amylases / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000494:pharmacology / Q000502:physiology*; D002463:Cell Membrane Permeability / Q000187:drug effects; D000242:Cyclic AMP / Q000037:antagonists & inhibitors / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D007700:Kinetics; D008297:Male; D010179:Pancreas / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism / Q000502:physiology*; D047428:Protein Kinase Inhibitors; D011494:Protein Kinases / Q000378:metabolism / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley
D047428:Protein Kinase Inhibitors; D000242:Cyclic AMP; D011494:Protein Kinases; D011493:Protein Kinase C; D000681:Amylases; D002118:Calcium