Ca^<2+>-Sensitivity of Portal Vein Circular Muscle from Normotensive and Hypertensive Rats

概要

論文の詳細を見る
Contractile sensitivity to Ca^<2+> was studied in rat portal vein circular muscle isolated from normotensive Wistar Kyoto rats (WKY) and stroke-prone spontaneously hypertensive rats (SHRSP). There was no difference in resting membrane potential between WKY and SHRSP. Elevation of extracellular K^+ concentration induced similar increase in tension in preparations from WKY and SHRSP. High K^+-depolarized preparation developed tension increase when extracellular Ca^<2+> concentration was increased. The sensitivity to extracellular Ca^<2+> was similar in preparations from WKY and SHRSP. Permeabilized preparation contracted when free Ca^<2+> concentration was increased. Sensitivity of permeabilized preparation to Ca^<2+> was similar in preparations from WKY and SHRSP. These results indicate that regulation of contraction by Ca^<2+> was similar between WKY and SHRSP. Since there was no change in high K-induced contraction in intact preparations or Ca-induced contraction in permeabilized preparations, there seemed to be no difference in Ca^<2+> influx via voltage-dependent channels in portal vein circular muscle from WKY and SHRSP.
日本平滑筋学会の論文