Dietz H, Halangk W, Bohnensack R, Kemnitz P
Institut für Biochemie, Medizinischen Akademie Magdeburg.
Dtsch Tierarztl Wochenschr. 1993 Jun;100(6):231-4.
The treatment of bull spermatozoa from epididymal cauda with 5 micrograms digitonin per microliters cells led to the destruction of the plasma membrane which was shown by electron microscopy. Structural changes of mitochondria and of the axoneme were not found. The functional intactness was maintained. The plasma membranes of hypotonically treated spermatozoa were permeable for succinate and the mitochondria showed a diminished functional intactness. For the total ATPase activity of digitonin-treated cells, mainly representing the dynein ATPase, a maximal activity of 20.3 nmol ATP x min-1 x microliters cells-1 (mean +/- S.D.; n = 8) and an apparent half saturation constant of 0.29 mM ATP were determined. The portions of Na(+)-K(+)-ATPase and mitochondrial ATPase in the total ATP-splitting activity were found to be less than 15%. In comparison to the capacity of mitochondrial ATP production, the maximal activity of ATP consuming reactions amounted to about 70%. These results support findings that the ATP turnover of spermatozoa is more limited by the ATP consumption than by the ATP production.
用每微升细胞5微克洋地黄皂苷处理附睾尾的公牛精子，导致质膜破坏，这在电子显微镜下得到证实。未发现线粒体和轴丝的结构变化。功能完整性得以维持。经低渗处理的精子质膜对琥珀酸具有通透性，线粒体的功能完整性有所降低。对于洋地黄皂苷处理细胞的总ATP酶活性（主要代表动力蛋白ATP酶），测定其最大活性为20.3 nmol ATP×min⁻¹×微升细胞⁻¹（平均值±标准差；n = 8），表观半饱和常数为0.29 mM ATP。发现Na⁺-K⁺-ATP酶和线粒体ATP酶在总ATP水解活性中的比例小于15%。与线粒体ATP产生能力相比，ATP消耗反应的最大活性约为70%。这些结果支持了这样的发现，即精子的ATP周转更多地受到ATP消耗的限制，而非ATP产生的限制。
