The Cycling of Calcium, Sodium, and Protons Across the Inner Membrane of Cardiac Mitochondria
Year: 1978
Type: article
Abstract: A method is described that permits simultaneous determination of the net charge transfer associated with Ca2+ transport by the ruthenium-red-sensitive carrier and the ionized internal [Ca2+] in heart mitochondria. The data indicate that this carrier catalyses a charge-uncompensated flux of Ca2+. Full charge compensation for Ca2+ influx is provided by the respiration-dependent efflux of H+. The net efflux of Ca2+ induced by Na+ is analysed in terms of two other carriers, a Na+-Ca2+ antiporter and a Na+-H+ antiporter. Evidence is presented that these two carriers are separate and that the Na+-H+ exchange is the more rapid. The fluxes of Ca2+, Na+ and H+ during the Na+-induced efflux of Ca2+ support a series of events in which the Na+-H+ exchange enables unidirectional Ca2+ fluxes via the uniport and antiport systems to be integrated into a cycle.
Source: European Journal of Biochemistry
Authors: Martin CROMPTON, Irma HEID
Institution: ETH Zurich
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: bronze
OpenAlex ID: W2002306733