Sordahl L A, Silver B B
Recent Adv Stud Cardiac Struct Metab. 1975;6:85-93.
Magnesium causes a marked decrease in the initial rates of respiration-supported calcium uptake by isolated heart mitochondria. Differential responses of mitochondrial respiration and cytochrome b redox states in the presence and absence of magnesium indicate that with magnesium present, heart mitochondria retain the ability to phosphorylate ADP after calcium uptake. Electron microscopy of the isolated mitochondria after calcium accumulation revealed markedly different crystal structures within the matrix space depending on the presence or absence of magnesium. The results suggest a "protective" effect of magnesium on the phosphorylating mechanism of mitochondria during active calcium uptake. Further, magnesium appears to determine the type of crystal structure formation within the intramitochondrial compartment.
镁会使离体心脏线粒体在呼吸支持下摄取钙的初始速率显著降低。在有镁和无镁情况下线粒体呼吸及细胞色素b氧化还原状态的不同反应表明，存在镁时，心脏线粒体在摄取钙后仍保留磷酸化二磷酸腺苷（ADP）的能力。钙积累后对分离出的线粒体进行电子显微镜观察发现，根据镁的存在与否，基质空间内的晶体结构明显不同。结果表明，镁在活跃的钙摄取过程中对线粒体的磷酸化机制具有“保护”作用。此外，镁似乎决定了线粒体内隔室内晶体结构形成的类型。
