Abstract
We have studied the effects of a synthetic peptide that is based on the autoinhibitory domain of protein kinase C on tension development in detergent-permeabilized coronary artery smooth muscle. This peptide inhibited two forms of protein kinase C that were isolated from the coronary artery media layer by hydroxylapatite chromatography, with apparent Ki values in the 5-8 microM range. Contractions induced by calcium in the permeabilized arteries were not affected by the peptide (30 microM). Potentiation of calcium-induced contractions by 1 microM phorbol-12,13-dibutyrate was partially inhibited by 10 microM peptide and was completely abolished by 30 microM peptide. These results indicate that phorbol-12,13-dibutyrate potentiates calcium-induced contractions of permeabilized coronary arteries by activation of protein kinase C, but activated protein kinase C is not a requirement for the induction of contractions by calcium alone.
MolPharm articles become freely available 12 months after publication, and remain freely available for 5 years.Non-open access articles that fall outside this five year window are available only to institutional subscribers and current ASPET members, or through the article purchase feature at the bottom of the page.
|