ACROSOMAL ENZYMES OF HUMAN-SPERMATOZOA BEFORE AND AFTER INVITRO CAPACITATION
ACROSOMAL ENZYMES OF HUMAN-SPERMATOZOA BEFORE AND AFTER INVITRO CAPACITATION
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DOI：
10.1095/biolreprod28.5.1032
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发表时间：
1983-01-01
影响因子：
3.6
通讯作者：
ZANEVELD, LJD
中科院分区：
文献类型：
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作者：
MACK, S;BHATTACHARYYA, AK;ZANEVELD, LJD
测定了体外获能(发生在顶体反应之前的事件)对人精子顶体酶的影响。人类精子的获能能力是通过它们穿透裸露的仓鼠卵母细胞的能力来评估的。测定了一些与精子顶体有关的酶的活性，包括非酶原顶体酶、顶体酶原、抑制物结合的顶体酶、透明质酸酶、酸性磷酸酶、β-葡萄糖苷酶、β-葡萄糖苷酶、β-N-乙酰氨基葡萄糖苷酶、β-半乳糖苷酶和β-N-乙酰半乳糖苷酶。精子在获能条件下孵育4h后，虽然发生了配子融合，但酶活性除酸性磷酸酶外，无明显变化。酸性磷酸酶水平下降了2倍，可能是由于精液(前列腺)酸性磷酸酶的丧失，这种酸性磷酸酶松散地附着在精子上。获能8h后，精子酶水平仅在透明质酸酶的情况下有较大幅度的下降，但总顶体酶、原顶体酶和抑制顶体酶的水平也略有下降。没有观察到新的顶体酶的电泳性迁移形式。当精子在非获能条件下孵育8h时，顶体酶和顶体酶原的含量下降，但抑制的顶体酶的含量没有下降，表明获能可能特异性地导致人精子释放某些顶体酶抑制物。除了透明质酸酶，人类精子的体外获能不会引起其顶体酶含量的重大变化，因此在配子融合期间顶体反应发生之前，这些水解酶就完全存在了。当精子在无人血清白蛋白的培养液中孵育8h时，几种糖苷酶的活性显著降低，因此血清白蛋白似乎可以防止其中一些酶的丧失。
The effect of in vitro capacitation (events that occur before the acrosome reaction) on the acrosomal enzymes of human spermatozoa was determined. Capacitation of human spermatozoa was assessed by their ability to penetrate denuded hamster oocytes. The activities of a number of enzymes commonly associated with the sperm acrosome including nonzymogen acrosin, proacrosin, inhibitor-bound acrosin, hyaluronidase, acid phosphatase, .beta.-glucuronidase, .beta.-glucosidase, .beta.-N-acetylglucosaminidase, .beta.-galactosidase and .beta.-N-acetylgalactosaminidase were assessed. With the exception of acid phosphatase, no alteration in enzyme activity occurred after 4 h of incubating the spermatozoa under capacitation conditions, although gamete fusion took place. The acid phosphatase levels decreased 2-fold, presumably due to the loss of seminal (prostatic) acid phosphatase that loosely adheres to spermatozoa. After 8 h of capacitation, a large decrease in sperm enzyme levels took place only in the case of hyaluronidase, although small decreases were also noted in total acrosin, proacrosin and inhibited acrosin. No new electrophoretically migrating forms of acrosin were observed. Decreases in total acrosin and proacrosin, but not in inhibited acrosin, also occurred when spermatozoa were incubated under noncapacitating conditions for 8 h, indicating that capacitation may specifically cause the release of some acrosin inhibitor from human spermatozoa. With the possible exception of hyaluronidase, the in vitro capacitation of human spermatozoa does not cause a major change in its acrosomal enzyme content so that these hydrolases are fully present before the acrosome reaction takes place during gamete fusion. Serum albumin appeared to protect against the loss of some of these enzymes since the activity of several glycosidases was significantly reduced when the spermatozoa were incubated for 8 h in human serum albumin-free medium.