Study ofion channels involved in uterine smooth muscle cells contraction by using molecular physiological approach

2007 Fiscal Year Final Research Report Summary

• Project/Area Number: 17591714
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Obstetrics and gynecology
• Research Institution: Yamagata University
• Principal Investigator: TAKAHASHI Toshifumi Yamagata University, School of Medicine, Associate professor (20302292)
• Co-Investigator(Kenkyū-buntansha): TSUTSUMI Seiji Yamagata University, School of Medicine, Associate professor (50323168) ; KURACHI Hirohisa Yamagata University, School of Medicine, Professor (40153366)
• Project Period (FY): 2005 – 2007
• Keywords: Ion channels / Smooth muscle cells / Pregnancy / Calcium channel / Potasium channel

Research Abstract

This is the last year of this study. So we analyzed the results taken from the experiments described below. First, we performed the experiment of expression of ion channels in pregnant smooth muscle cells; Expression of calcium channels, such as inositol tri-phosphate (IP3) receptors and ryanodine receptors; Expression of sodium and potassium channels. Expression of calcium channels, such as IN and ryanodine receptors in rat myometrium were increased with increasing gestational age. Second, we performed the experiment of the effects of oxytocin and beta-stimulant on pregnant myometrium by using electrophysiological approach. Third, we performed the experiment of the effects of oxytocin and beta-stimulants on intracellular calcium concentrations in pregnant myometrium. The intracellular calcium concentration in pregnant myometrium was increased dose-dependently by treatment of oxytocin. The increased calcium concentration induced by oxytocin was inhibited by treatment of beta-stimulants. These results suggest that the expression and function of various ion channels in smooth muscle cells are modulated by gestational age.