Constriction of Retinal Venules to Endothelin-1: Obligatory Roles of ET_A Receptors, Extracellular Calcium Entry, and Rho Kinase

Abstract

Extracellular Ca2+ entry via L-VOCCs is essential for developing and maintaining basal tone of porcine retinal venules. ET-1 causes significant constriction of retinal venules by activating ETARs and extracellular Ca2+ entry independent of L-VOCCs. Activation of ROCK signaling, without involvement of PKC, appears to mediate venular constriction to ET-1 in the porcine retina.