棉酚对体外家兔精子顶体酶类的抑制作用

本文对棉酚体外抑制１０种家兔精子顶体酶活性进行了测定。当醋酸棉酚浓度为１２～７６μｍｏｌ／Ｌ时，可完全或明显抑制顶体酶（ａｃｒｏｓｉｎ）、Ａｚｏｃｏｌｌ蛋白酶、芳香基硫酸酯酶和神经氨酸苷酶活性；而当浓度高达３８０μｍｏｌ／Ｌ时才能抑制透明质酸酶、β－葡糖苷酸酶和酸性磷酸酶，但不抑制磷酸酯酶Ｃ、碱性磷酸；酶和β－Ｎ－乙酰氨基葡糖苷酶。棉酚对芳香基硫酸酯酶的抑制作用是一种非竞争性抑制作用，Ｋｉ为１２０μｍｏｌ／Ｌ。其抑制作用是可逆的，呈剂量依赖关系。由于抑制家兔精子顶体酶所需棉酚浓度比精子糖酵解或能量代谢酶要低，因此，这些敏感酶似可作为监护棉酚引起不育的指标。

Inhibition of Gossypol on Rabbit Sperm Acrosomal Enzymes in Vitro

The effect of gossypol on the activities of ten acrosornal enzymes of the rabbit sperm was evaluated. Acrosin .Azocoll proteinsae 、neuraminidase and arylsulfatase were significantly inhibited or completely inactivated by 12￣76 μmol/L gossypol. Hyaluronidase, μ- glucuronidase and acid phosphatase were inhibited only at a higher concentration of gossypol (380 μmol/L). Phospholipase C, alkaline phosphatase and β- N - Acetyl glucosaminidase were not inhibited even at 380 μmol/L gossypol. Gossypol was found to be a noncompetitive inhibitor of arylsulfatase with a Ki of 120 μmol/L.The inhibition was reversible and dose - dependent. As the acrosomal enzymes were more sensitive to the inhibition by gossypol compared to sperm enzymes involved in glycolysis or energy production, these assays may serve as a more reliable indicator for monitoring the occurrence of gossypol - induced sterility.