Activation of protein kinase C is not an absolute requirement for amylase release from permeabilized rat pancreatic acini

Biochem J. 1992 Jul 15;285 ( Pt 2)(Pt 2):597-601. doi: 10.1042/bj2850597.

Abstract

The effect of protein kinase C (PKC) on amylase discharge from streptolysin-O-permeabilized rat pancreatic acini was investigated. Addition of phorbol 12-myristate 13-acetate (PMA) to permeabilized cells potentiated Ca(2+)-stimulated release, but had no effect on discharge at non-stimulatory Ca2+ concentrations. PMA markedly shifted the Ca(2+)-concentration-dependence of amylase discharge to the left, by enhancing the time over which the permeabilized cells release. This effect was inhibited by both staurosporine and PKC-19-31-amide peptide inhibitor, indicating that the effect of PMA was due to its action on PKC. Staurosporine also partially inhibited amylase release at the optimal concentration of Ca2+; this effect was not replicated by the more specific PKC-19-31-amide peptide inhibitor and may be due to an effect on another second-messenger system. PKC appears to be an important modulator of release in pancreatic acini, but its activation is not an absolute requirement for Ca(2+)-dependent amylase discharge.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Alkaloids / pharmacology
  • Amylases / metabolism*
  • Animals
  • Calcium / metabolism
  • Cations, Divalent
  • Cyclic AMP / pharmacology
  • Enzyme Activation
  • Male
  • Pancreas / drug effects
  • Pancreas / enzymology*
  • Peptides / pharmacology
  • Protein Kinase C / antagonists & inhibitors
  • Protein Kinase C / metabolism*
  • Rats
  • Rats, Inbred Strains
  • Staurosporine
  • Tetradecanoylphorbol Acetate / pharmacology

Substances

  • Alkaloids
  • Cations, Divalent
  • Peptides
  • protein kinase inhibitor peptide
  • Cyclic AMP
  • Protein Kinase C
  • Amylases
  • Staurosporine
  • Tetradecanoylphorbol Acetate
  • Calcium