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Title: A pseudosubstrate of PKC inhibits the phorbol dibutyrate (PDBu) effect on permeabilized smooth muscle

Phorbol esters can induce contraction of vascular smooth muscle and potentiate calcium-induced contractions of permeabilized smooth muscle strips. The authors have used a synthetic peptide inhibitor based on residues 19-31 of PKC (PKC-I) to determine the importance of PKC in the PDBu potentiation of calcium-induced contractions in permeabilized coronary artery smooth muscle. Although peptides similar to PKC-I have been shown to also inhibit MLCK in vitro, MLCK was presumably not inhibited in our system since 30 {mu}M PKC-I alone did not alter the calcium-induced contractions. However, the potentiation of these contractions by 1 {mu}M PDBu was reduced by about 50% in the presence of 10 {mu}M PKC-I, and the potentiation was completely abolished by 30 {mu}M PKC-I. These data indicate that, in this system, PKC is not involved in calcium-induced contractions but that activation of PKC may be the mechanism by which PDBu potentiates calcium-induced contractions in permeabilized coronary artery smooth muscle.
Authors:
;  [1]
  1. (Vanderbilt Univ., Nashville, TN (United States))
Publication Date:
OSTI Identifier:
5374034
Report Number(s):
CONF-9104107--
Journal ID: ISSN 0892-6638; CODEN: FAJOE
Resource Type:
Conference
Resource Relation:
Journal Name: FASEB Journal (Federation of American Societies for Experimental Biology); (United States); Journal Volume: 5:4; Conference: 75. annual meeting of the Federation of American Societies for Experimental Biology (FASEB), Atlanta, GA (United States), 21-25 Apr 1991
Country of Publication:
United States
Language:
English
Subject:
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.; MUSCLES; CONTRACTION; PEPTIDES; BIOCHEMICAL REACTION KINETICS; PHORBOL ESTERS; BIOLOGICAL EFFECTS; CALCIUM; CORONARIES; INHIBITION; PERMEABILITY; ALKALINE EARTH METALS; ARTERIES; BLOOD VESSELS; BODY; CARCINOGENS; CARDIOVASCULAR SYSTEM; ELEMENTS; ESTERS; KINETICS; METALS; ORGANIC COMPOUNDS; ORGANS; PROTEINS; REACTION KINETICS 560300* -- Chemicals Metabolism & Toxicology