Halangk W, Dietz H
Biomed Biochim Acta. 1986;45(10):1249-57.
Treatment of bull spermatozoa from epididymal cauda with 5 micrograms digitonin per microliter cells removed the permeability barrier of plasma membrane for mitochondrial substrates and effectors. Such preparations yielded a high portion of coupled mitochondria characterized by ratios of active respiration to carboxyatractyloside-inhibited respiration greater than 13 in the presence of efficient substrates. Bull sperm mitochondria oxidized pyruvate and lactate in the presence of malate as well as glycerol-3-phosphate with much higher rates than succinate or palmitoyl carnitine. For the efficient substrates the respiration coupled to ADP phosphorylation amounted to 77 to 100% of the uncoupled rate. Comparable rates of active respiration were also observed with ATP indicating the high ATPase activity present in digitonin-treated spermatozoa. Uncoupled rates of respiration corresponded to rates of intact spermatozoa, but the capacity of the phosphorylating respiration exceeded the respiration rates of intact motile spermatozoa remarkably. This indicates that the spermatozoal ATP turnover at sufficient supply of substrate is mostly controlled by ATP utilizing reactions.
用每微升细胞5微克的洋地黄皂苷处理来自附睾尾的公牛精子，去除了质膜对线粒体底物和效应物的通透性屏障。这样的制剂产生了很大一部分偶联线粒体，在存在有效底物的情况下，其活性呼吸与羧基苍术苷抑制呼吸的比率大于13。公牛精子线粒体在苹果酸存在下氧化丙酮酸和乳酸以及甘油-3-磷酸的速率比琥珀酸或棕榈酰肉碱高得多。对于有效底物，与ADP磷酸化偶联的呼吸量占解偶联速率的77%至100%。用ATP也观察到了相当的活性呼吸速率，表明洋地黄皂苷处理的精子中存在高ATP酶活性。解偶联呼吸速率与完整精子的速率相当，但磷酸化呼吸能力明显超过完整活动精子的呼吸速率。这表明在底物供应充足时，精子的ATP周转主要受ATP利用反应的控制。
