Rugolo M, Siliprandi D, Siliprandi N, Toninello A
Biochem J. 1981 Dec 15;200(3):481-6. doi: 10.1042/bj2000481.
Addition of Ruthenium Red to energized rat liver mitochondria that have previously accumulated Ca2+ and phosphate from the external medium induces a parallel efflux of both these ions. Mersalyl or dithioerythritol, which decrease Ruthenium Red-insensitive Ca2+ efflux, also decrease phosphate efflux to the same extent. Conversely diazenedicarboxylic acid bis(NN-dimethylamide) (DDBA), which increases the Ruthenium Red-induced Ca2+ efflux concurrently increases phosphate release. Dithioerythritol and DDBA, reducing and oxidizing agents of thiol groups respectively, modify Ca2+ and Pi efflux without penetrating the mitochondrial inner membrane. Under all the adopted conditions the membrane potential is preserved. The release of resting respiration and the parallel efflux of Mg2+ and adenine nucleotides, events closely correlated to Ca2+ cycling, are equally prevented either by mersalyl, which inhibits phosphate transport, or dithioerythritol; DDBA has the opposite effect. These findings and the observation that suggest that Ca2+ and phosphate transport in energized liver mitochondria are closely related and dependent on the redox state of membrane-bound thiol groups.
向预先已从外部介质中积累了钙离子和磷酸根的活性大鼠肝脏线粒体中添加钌红，会引发这两种离子的平行外流。汞撒利或二硫苏糖醇会减少对钌红不敏感的钙离子外流，同时也会在相同程度上减少磷酸根外流。相反，重氮二羧酸双（N，N - 二甲基酰胺）（DDBA），它会增加钌红诱导的钙离子外流，同时也会增加磷酸根的释放。二硫苏糖醇和DDBA，分别是巯基的还原剂和氧化剂，它们在不穿透线粒体内膜的情况下改变钙离子和磷酸根的外流。在所有采用的条件下，膜电位均得以维持。汞撒利（它抑制磷酸根转运）或二硫苏糖醇同样能阻止静息呼吸的释放以及镁离子和腺嘌呤核苷酸的平行外流，这些事件与钙离子循环密切相关；而DDBA则有相反的作用。这些发现以及相关观察表明，活性肝脏线粒体中的钙离子和磷酸根转运密切相关，且依赖于膜结合巯基的氧化还原状态。
