The Korean Journal of Physiology
- Volume 21 Issue 2
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- Pages.179-189
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- 1987
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- 0300-4015(pISSN)
Mechanism of Inhibition of Cardiac Muscle Contractility by Ryanodine
심근 수축력 저하를 유발하는 Ryanodine의 작용 기전
- Ahn, Duck-Sun (Department of Physiology, College of Medicine, Yonsei University) ;
- Suh, Chang-Kook (Department of Physiology, College of Medicine, Yonsei University) ;
- Kang, Doo-Hee (Department of Physiology, College of Medicine, Yonsei University)
- Published : 1987.12.30
Abstract
Since it has been known that ryanodine has a potent negative inotropic effect on the cardiac muscle contractility (Jenden and Fairhurst, 1968), ryanodine has been a subject of intensive research (Frank and Sleator, 1975; Jones et al, 1978; Sutko et al, 1985). However, the underlying mechanism for the ryanodine dependent negative inotropic effect is still uncertain. In this study, the effects of ryanodine on the generation and relaxation of contracture due to Na-withdrawal and on the force-frequency relationship of heart muscles isolated from rats and guinea pigs were measured in an effort to understand the underlying mechanism of the ryanodine-induced negative inotropy. Results are summerized as follows: 1 ) Ryanodine significantly reduced the contractility of heart muscles produced at low frequency of stimulation, but showed a little effect on the contractility at high frequency stimulation. 2) Ryanodine, at the concentrations ranging from