Referenced in: none

Automatically associated channels: Slo1

Title: Vasodilatory mechanisms of unoprostone isopropyl in isolated porcine retinal arterioles.

Authors: Ichiro Tanano, Taiji Nagaoka, Shinji Ono, Tsuneaki Omae, Shinichi Otani, Akitoshi Yoshida

Journal, date & volume: Mol. Vis., 2015 , 21, 699-705

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/26120274

Abstract
To clarify the vasodilatory mechanism of unoprostone isopropyl (UI), we examined its effects on the retinal microvascular diameter to determine the dependence on the endothelium and/or smooth muscle to reveal the signaling mechanisms involved in this vasomotor activity.Porcine retinal arterioles were isolated, cannulated, and pressurized without flow in vitro. Video microscopic techniques recorded the diametric responses to UI.The retinal arterioles dilated in response to UI in a dose-dependent (100 pM-10 µM) manner. The nitric oxide (NO) synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME) inhibited UI-induced vasodilation. The large-conductance Ca2+-activated K channel (BKCa channel) blocker iberiotoxin also inhibited UI-induced vasodilation. The residual vasodilation after L-NAME was eliminated with co-administration of iberiotoxin.UI elicits dilation of the retinal arterioles mediated by NO release and BKCa channel activation.