Vercesi A, Lehninger A L
Biochem Biophys Res Commun. 1984 Jan 13;118(1):147-53. doi: 10.1016/0006-291x(84)91079-9.
Inorganic pyrophosphate (PPi) in the intracellular concentration range causes rapid efflux of Ca2+ from rat heart mitochondria oxidizing pyruvate + malate in a low Na+ medium. Half-maximal rates of Ca2+ efflux were given by 20 microM PPi. During and after PPi-stimulated Ca2+ efflux the mitochondria retain their structural integrity and complete respiratory control. Carboxyatractyloside inhibits PPi-stimulated Ca2+ efflux, indicating PPi must enter the matrix in order to promote Ca2+ efflux. Heart mitochondria have a much higher affinity for PPi uptake and PPi-induced Ca2+ efflux than liver mitochondria.
细胞内浓度范围内的无机焦磷酸（PPi）可使大鼠心脏线粒体在低钠培养基中氧化丙酮酸+苹果酸时快速排出Ca2+。20微摩尔PPi可产生半数最大Ca2+外排速率。在PPi刺激Ca2+外排期间及之后，线粒体保持其结构完整性并维持完全的呼吸控制。羧基苍术苷抑制PPi刺激的Ca2+外排，表明PPi必须进入线粒体基质才能促进Ca2+外排。心脏线粒体对PPi摄取和PPi诱导的Ca2+外排的亲和力比肝脏线粒体高得多。
