토끼 심방근 세포막의 Na/Ca교환 비율에 관한 연구

• 영문명: A Study on Na/Ca Exchange Ratio in Atrial Muscle of Rabbit
• 발행기관: 대한생리학회
• 저자명: 김의용(Kim, Eui-Yong) 황상익(Hwang, Sang-Ik) 엄융의(Earm, Yung-E) 성호경(Sung, Ho-Kyung)
• 간행물 정보: 『대한생리학회지』제23권 제2호, 291~300쪽, 전체 10쪽
• 주제분류: 의약학 > 의학일반
• 파일형태: PDF
• 발행일자: 1989.12.31

영문 초록

Na and Ca effects on contracture were studied in order to estimate Na/Ca exchange ratio in the isolated atrial muscle of the rabbit. All experiments were performed in tris-buffered Tyrode solution which was being aerated with 100% O₂ and kept at 37˚C. To load intracellular Na⁺, 10^-6M ouabain or K-free solution were used. Contractures were induced by brier exposure of atrial muscle to Tyrode solution containing various concentrations of Ca or of Na. The results obtained were as follows: 1 ) Increasing the extracellular Ca concentration, the amplitude of contracture also increased and was maximum at 8 mM Ca-Tyrode solution. 2) The relationship between extracellular Ca concentrations and relative amplitude of the contractures showed hyperbolic pattern. By using Hill plot, the line has the slope of 1 12 which means the number of Ca binding sites of the carrier in the cell membrane. 3) The amplitude of the contracture was maximum in 0 mM Na-Tyrode solution and decreased in dose dependent manner when the Na concentration increased. 4) When the relationship between extracellular Na concentrations and the amplitude of contractures was expressed as dose-response curve, the curve showed sigmoid pattern. The line with the slope of 2.82 was obtained by using Hill plot. 5) From above all the results, it is suggested that exchange ratio of Na and Ca via Na/ca exchange system in the atrial muscle of rabbit could be 3:1 approximately.

키워드

Na-free contracture Ca-contracture Na/Ca exchange ratio