Constriction of Retinal Arterioles to Endothelin-1: Requisite Role of Rho Kinase Independent of Protein Kinase C and L-Type Calcium Channels

Abstract

Extracellular Ca²⁺ entry via L-VOCCs and basal ROCK activity play important roles in the maintenance of basal tones of porcine retinal arterioles. ET-1-induced constriction is mediated by extracellular Ca²⁺ entry independent of L-VOCCs and by ROCK activation without the involvement of PKC. However, direct PKC activation can cause vasoconstriction via L-VOCC and ROCK signaling.