Effects of Na+ and Ca2+ concentration in cardioplegic and reperfusion solutions on the intracellular Ca2+ of cardiac muscle cells.
The removal of Ca2+ from the cardioplegic solutions could cause the danger of inducing a "calcium paradox" during reperfusion. Since intracellular Ca2+ activities are coupled to Na+ activities via Na(+)-Ca2+ exchange, an increase in intracellular Na+ activities during the cardioplegia could cause an abrupt Ca2+ influx when reperfused. To study the effects of Na+ and Ca2+ concentrations in cardioplegic solutions on intracellular Ca2+ activities during the cardioplegia and subsequent recovery period, the membrane potential and intracellular Na+ and Ca2+ activities of guinea pig ventricular papillary were measured. 1) A cardioplegia with low Ca2+ cardioplegic solution significantly decreased the overshoot and duration of the first action potential after cardioplegia, but the changes in action potential configuration were minimized after a cardioplegia with Ca2+ concentration adjusted according to the Na(+)-Ca2+ exchange mechanism. 2) Intracellular Na+ activity was continuously decreased during the cardioplegia, and the intracellular Na+ activity 20 minutes after cardioplegia was the highest with low Ca2+ cardioplegic solution. 3) Intracellular Na+ and Ca2+ activities were continuously decreased during the cardioplegia with Ca2+ concentration adjusted according to the Na(+)-Ca2+ exchange mechanism. 4) During a reperfusion of Tyrode solution after cardioplegia intracellular Na+ and Ca2+ activities were increased. Intracellular Ca2+ activity was increased more rapidly than intracellular Na+ activity. 5) The rate of increase in intracellular Ca2+ activity with reperfusion of Tyrode solution was dependent upon intracellular Na+ activity during cardioplegia, in such a way that the higher the intracellular Na+ activity was, the faster the intracellular Ca2+ activity increased. These data suggest that Na(+)-Ca2+ exchange mechanism may play an important role in the regulation of intracellular Ca2+ activity during recovery after cardioplegia.
유료 다운로드의 경우 해당 사이트의 정책에 따라 신규 회원가입, 로그인, 유료 구매 등이 필요할 수 있습니다. 해당 사이트에서 발생하는 귀하의 모든 정보활동은 NDSL의 서비스 정책과 무관합니다.
원문복사신청을 하시면, 일부 해외 인쇄학술지의 경우 외국학술지지원센터(FRIC)에서
무료 원문복사 서비스를 제공합니다.
NDSL에서는 해당 원문을 복사서비스하고 있습니다. 위의 원문복사신청 또는 장바구니 담기를 통하여 원문복사서비스 이용이 가능합니다.
- 이 논문과 함께 출판된 논문 + 더보기