Regulation of abalone sperm cyclic AMP concentrations and the acrosome reaction by calcium and methylxanthines.
Regulation of abalone sperm cyclic AMP concentrations and the acrosome reaction by calcium and methylxanthines.
复制标题
钙和甲基黄嘌呤调节鲍鱼精子环磷酸腺苷浓度和顶体反应。
DOI：
10.1016/0012-1606(83)90332-9
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发表时间：
1983
影响因子：
2.7
通讯作者：
Vacquier,VD
中科院分区：
文献类型：
--
作者：
Kopf,GS;Lewis,CA;Vacquier,VD
当将 Ca2+ 添加到不含 Ca2+ 的人工海水 (CaFASW) 中的鲍鱼精子 (Haliotis rufescens) 中，最终浓度达到 9.6 mMa 时，精子中的 cAMP 在 15-30 秒内就会升高 4 倍。甲基黄嘌呤、茶碱和 1-甲基-3-异丁基黄嘌呤 (MIX) 也会提高精子 cAMP 浓度。在 CaFASW 中，任一化合物均可在 15-30 秒内使 cAMP 增加 3 倍。在存在 9.6 mMCa2+ 的情况下将 MIX (150 μM) 添加到精子中，可在 15-30 秒内将精子 cAMP 升高 100 倍，并在同一时期触发顶体反应 (AR)。在相同条件下，茶碱 (1.67 mM) 在升高 cAMP 和诱导 AR 方面的效力要弱得多。甲基黄嘌呤对在 Ca2+ 存在下孵育的精子 cAMP 的影响似乎代表了这些化合物对 Ca2+ 作用的增强。在没有 Ca2+ 的情况下，这两种化合物都不会诱导 AR。所有观察到的对精子 cAMP 和 AR 的影响都取决于 Ca2+ 和甲基黄嘌呤浓度。无论存在或不存在 Ca2+，添加的环核苷酸或其衍生物都不会诱导 AR。用分离的精子头部和鞭毛进行的实验表明，精子 cAMP 对 Ca2++ MIX 的剧烈刺激反应存在于细胞的头部区域（顶体、细胞核、中段）。数据表明，在存在 Ca2+ 的情况下，MIX 显着升高 cAMP 可能是通过抑制磷酸二酯酶活性直接发生的，也可能是通过增加细胞 Ca2+ 间接发生的。 cAMP 升高和鲍鱼 AR 之间存在很强的时间相关性，尽管 cAMP 升高本身并不充当该胞吐事件的主要介质。
When Ca2+is added to abalone sperm (Haliotis rufescens) in Ca2+-free artificial seawater (CaFASW) to a final concentration of 9.6 mMa 4-fold elevation in sperm cAMP occurs within 15–30 sec. The methylxanthines, theophylline and 1-methyl-3-isobutylxanthine (MIX), also elevate sperm cAMP concentrations. In CaFASW, either compound causes up to a 3-fold increase in cAMP within 15–30 sec. MIX (150 μM), added to sperm in the presence of 9.6 mMCa2+, elevates sperm cAMP 100-fold within 15–30 sec and also triggers the acrosome reaction (AR) in the same period. Under identical conditions theophylline (1.67 mM) is much less potent at elevating cAMP and inducing the AR. The effects of methylxanthines on cAMP of sperm incubated in the presence of Ca2+appear to respresent a potentiation by these compounds of the action of Ca2+. Neither compound induces the AR in the absence of Ca2+. All of the observed effects on sperm cAMP and the AR are dependent on Ca2+and methylxanthine concentrations. Added cyclic nucleotides or their derivatives do not induce the AR in either the absence or presence of Ca2+. Experiments with isolated sperm heads and flagella indicate that the dramatic stimulatory response of sperm cAMP to Ca2+plus MIX is present in the head region (acrosome, nucleus, midpiece) of the cell. The data suggest that the dramatic elevation of cAMP by MIX in the presence of Ca2+may occur directly by an inhibition of phosphodiesterase activity and indirectly by an increase in cellular Ca2+. A strong temporal correlation between the cAMP elevation and the abalone AR exists, although cAMP elevation by itself does not act as the primary mediator of this exocytotic event.