The interrelationship between sodium and calcium fluxes across cell membranes.
The interrelationship between sodium and calcium fluxes across cell membranes.
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DOI：
10.1007/bfb0034293
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发表时间：
1974-01-01
期刊：
影响因子：
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通讯作者：
Blaustein, M P
中科院分区：
文献类型：
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作者：
Blaustein, M P
林格(1883年)的经典实验首次提供了钙在生理过程中发挥作用的证据。近年来，有关钙离子在细胞内的作用已积累了大量的数据，并发表了大量的综述。现在人们认识到，钙可能在细胞呼吸中发挥重要作用(例如Lehninger等人，1967；CARAFOLI和Rossi，1971)。钙离子是肌肉收缩(如EBASHI和Endo，1968；Costantin，1974)以及多种分泌细胞(如Douglas，1969；Rubin，1970)和神经末梢(如Katz，1969)兴奋与分泌耦合所必需的。它们对于维持可兴奋膜的“稳定性”是必需的(如Shift，S，1958a，b；Bianci，1968)，在许多类型的可兴奋细胞中，钙离子携带着与去极化相关的大部分内向电流(如R~UTZE.，1973)。最后，钙对膜通透性有显著的影响：增加细胞内钙使细胞间连接解偶联(LOEWENSTEm等，1967；Oliveira-Castro和Loewenstein，1971；Loewenstein，1973)，并增加许多类型细胞的钾通透性(例如Gardos，1959；KREGENOW和Hoffman，1971；Romero和Whittam，1971；Meech，1972；KRNJEVlC和LISlEWICZ，1972；Jansen和Nicholls，1973)。尽管关于钙的生理作用有如此丰富的信息，但人们对控制钙跨细胞膜移动的机制以及控制静息细胞内游离钙浓度的机制知之甚少。在过去的几年里，来自一些实验室的数据提供了证据，表明在许多类型的细胞中，钙的运输可能至少部分涉及钠离子与钙离子的交换。本文的主要目的是回顾这些数据，并讨论可能涉及的机制。在许多情况下，可获得的信息相当零碎，有时还存在争议。然而，这些观察结果中的大多数与这样的观点是一致的，即在许多类型的细胞中，一些“活跃的”钙转运的能量可能来自跨膜Na电化学梯度，而不是像Na-K偶联泵那样直接来自三磷酸腺苷(ATP)(例如Caldwell，1969；DE Weer，1973)。因此，钠梯度在钙转运中的可能作用可以与钠梯度在非电解质运输中的假定作用进行比较(例如Schultz和Curran，1970；Gibb和Eddy，1972；但参见Potashner和Johnstone，1971；Schafer和Heinz，1971；以及Geck等人，1972)。
The classical experiments of RINGER (1883) were the first to provide evidence that calcium plays a role in physiological processes. In recent years a considerable body of data on the cellular actions of Ca has been accumulated, and numerous reviews have appeared. It is now recognized that Ca may play a fundamental role in cellular respiration (eg LEHNINGER et al., 1967; CARAFOLI and RossI, 1971). Calcium ions are required for muscular contraction (eg EBASHI and ENDO, 1968; COSTANTIN, 1974), and for the coupling of excitation to secretion in a large variety of secretory cells (eg DOUGLAS, 1969; RUBIN, 1970) and at nerve endings (eg KATZ, 1969). They are necessary for the maintenance of excitable membrane" stability"(eg SHAft, S, 1958a, b; BIANCHI, 1968), and in many types of excitable cells, Ca ions carry much of the inward current associated with depolarization (eg R~ UTZe., 1973). Finally, Ca has a significant influence on membrane permeability: raising intracellular Ca uncouples intercellular connections (LOEWENSTEm et al., 1967; OLIVEIRA-CASTRO and LOEWENSTEIN, 1971; LOEWENSTEIN, 1973) and increases potassium permeability in many types of cells (eg GARDOS, 1959; KREGENOW and HOFFMAN, 1971; ROMERO and WHITTAM, 1971; MEECH, 1972; KRNJEVlC and LISlEWICZ, 1972; JANSEN and NICHOLLS, 1973). Despite this wealth of information on the physiological actions of Ca, relatively little is known about the mechanisms which govern the movements of Ca across cellular membranes, and which control the intracellular free Ca 2+ concentration in resting cells. During the past few years data from a number of laboratories have provided evidence that in many types of cells the transport of Ca may involve, at least in part, an exchange of sodium ions for Ca ions. The primary objective of this article is to review these data and to discuss the possible mechanisms involved. In many instances the available information is rather fragmentary, and sometimes controversial. Most of these observations are, however, consistent with the idea that in many types of cells some of the energy for" active" Ca transport may be derived from the transmembrane Na electrochemical gradient, rather than from adenosine triphosphate (ATP) directly as is the case for the Na-K coupled pump (eg CALDWELL, 1969; DE WEER, 1973). Thus, the possible role of the Na gradient in Ca transport may be compared with the postulated role of the Na gradient in non-electrolyte transport (eg SCHULTZ and CURRAN, 1970; GIBB and EDDY, 1972; but see POTASHNER and JOHNSTONE, 1971; SCHAFER and HEINZ, 1971; and GECK et al., 1972).