Effects of GS-386 on the calcium current in rabbit atrial myocytes

GS-386이 단일 심근 세포의 Ca2+ 전류에 미치는 효과

  • Park, Choon-ok (Department of Physiology and the Institute of Cardiovascular Research, College of Medicine, Gyeongsang National University) ;
  • Chang, Kyeong-jae (Department of Physiology and the Institute of Cardiovascular Research, College of Medicine, Gyeongsang National University) ;
  • Kim, Yang-mi (Department of Physiology and the Institute of Cardiovascular Research, College of Medicine, Gyeongsang National University) ;
  • Haan, Jae-hee (Department of Physiology and the Institute of Cardiovascular Research, College of Medicine, Gyeongsang National University) ;
  • Hong, Seong-geun (Department of Physiology and the Institute of Cardiovascular Research, College of Medicine, Gyeongsang National University)
  • 박춘옥 (경상대학교 의과대학 생리학교실, 심혈관연구소) ;
  • 장경재 (경상대학교 의과대학 생리학교실, 심혈관연구소) ;
  • 김양미 (경상대학교 의과대학 생리학교실, 심혈관연구소) ;
  • 한재희 (경상대학교 의과대학 생리학교실, 심혈관연구소) ;
  • 홍성근 (경상대학교 의과대학 생리학교실, 심혈관연구소)
  • Received : 1993.10.18
  • Published : 1994.01.31

Abstract

The effects of the novel compound GS-386 on the calcium current were investigated in rabbit atrial myocytes. The calcium current was recorded during various depolarizations of 200 ms duration from a holding potential of -40 mV using the whole cell patch clamp technique. The calcium current was activated from -30 mV, reached maximum amplitude at +10 mV and almost disappeared at +50 mV. Superfusion of GS-386 led to a reduction of the calcium current amplitude dose-dependently and $ED_{50}$ was $2.5{\times}10^{-7}M$. But the dependence of the calcium current on the membrane potential was not altered by GS-386. The inactivation of the calcium currents showed single exponential curves in both before and after application of GS-386. The inactivation time constants before and after application of GS-386 were almost the same(35 ms and 32.5 ms). The steady-state inactivation curve of the calcium current was not shifted by GS-386. The calcium currents both before and after application of GS-386 recovered completely in 1 sec and the recovery time constants were about 200 ms in both cases. From the above results it is concluded that the novel compound GS-386 has calcium antagonistic property decreasing the calcium current.

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