Insulin secretion: combined effects of phorbol ester and A23187

Biochem Biophys Res Commun. 1983 Dec 16;117(2):448-55. doi: 10.1016/0006-291x(83)91221-4.


The effect of the ionophore, A23187, and/or the phorbol ester, 12-O-tetradecanoyl-phorbol-13-acetate (TPA), on insulin secretion were compared with those of glucose. Glucose induces a biphasic pattern of insulin secretion; A23187 a comparable initial spike but no second phase; and TPA a slowly progressive increase. Combined A23187 and TPA evoke a pattern similar to that induced by glucose. Forskolin enhances both phases of glucose- induced and of TPA-A23187-induced insulin secretion. These results are interpreted in terms of a model of cell activation in which two branches of the calcium messenger system, the calmodulin branch and the C-kinase branch, control, respectively, the initial and sustained phases of insulin secretion.

Publication types

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

MeSH terms

  • Animals
  • Calcimycin / pharmacology*
  • Calmodulin / metabolism
  • Drug Synergism
  • Glucose / pharmacology
  • Insulin / metabolism*
  • Insulin Secretion
  • Islets of Langerhans / drug effects
  • Islets of Langerhans / metabolism*
  • Male
  • Phorbols / pharmacology*
  • Protein Kinase C
  • Protein Kinases / metabolism
  • Rats
  • Rats, Inbred Strains
  • Tetradecanoylphorbol Acetate / pharmacology*


  • Calmodulin
  • Insulin
  • Phorbols
  • Calcimycin
  • Protein Kinases
  • Protein Kinase C
  • Glucose
  • Tetradecanoylphorbol Acetate