Frontiers in Bioscience-Landmark (FBL) is published by IMR Press from Volume 26 Issue 5 (2021). Previous articles were published by another publisher on a subscription basis, and they are hosted by IMR Press on imrpress.com as a courtesy and upon agreement with Frontiers in Bioscience.
Academic Editor: Joseph Benoit
The involvement of protein kinase C (PKC) in isometric tension development of rat mesenteric arteries was investigated. Non-selective inhibition of PKC and selective inhibition of the epsilon isoform were performed using the PKC inhibitor, chelerythrine, and non-viral gene-transfer of a kinase inactive mutant of PKCepsilon (PKCepsilon-KN), respectively. Chelerythrine (2.5 or 5.0 microM) significantly and equally attenuated phenylephrine-induced but not potassium-induced contractions. Higher concentrations of chelerythrine (10 microM) caused the vessels to lose responsiveness to both phenylephrine and potassium chloride. Transfection of blood vessels with epsilon-KN also resulted in significant attenuation of contractile responses to phenylephrine. Potassium chloride-induced responses were not altered in transfected arteries. In a separate group of vessels, the relationship between [Ca2+]i and isometric tension was evaluated. These studies suggested that calcium sensitivity of the contractile apparatus was decreased in vessels when PKC-epsilon activity was compromised. The results of the study suggest that PKC-epsilon can modulate phenylephrine-induced contraction in mesenteric arteries via calcium-independent pathways.