The role of Ca2+ and cyclic nucleotides in progesterone initiation of the meiotic divisions in amphibian oocytes.
The role of Ca2+ and cyclic nucleotides in progesterone initiation of the meiotic divisions in amphibian oocytes.
复制标题
Ca2 和环核苷酸在黄体酮启动两栖类卵母细胞减数分裂中的作用。
DOI：
10.1016/0024-3205(81)90513-0
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发表时间：
1981
期刊：
影响因子：
6.1
通讯作者：
Kostellow,AB
中科院分区：
文献类型：
--
作者：
Morrill,GA;Ziegler,D;Kostellow,AB
黄体酮似乎是两栖动物卵母细胞减数分裂恢复的生理诱导剂。在暴露于孕酮后的几分钟内，Ca2+释放，[cAMP]短暂升高，随后[cAMP]下降，[cGMP]升高，在接下来的1-3小时内。诱导[cAMP]下降的药物诱导减数分裂，而阻止[cAMP]下降和/或升高[cAMP]的药物阻断减数分裂。通过比较注射的[3H]-ATP向[3H]-cAMP的转化，以及暴露于减数分裂激动剂和拮抗剂后注射的[3H]-cAMP的水解速率，表明腺苷酸环化酶而不是磷酸二酯酶是调节卵母细胞中[cAMP]的限速步骤。这些发现与孕激素通过从特定膜位点释放Ca2+下调膜腺苷酸环化酶启动减数分裂恢复的模型一致，Ca2+的易位产生鸟苷酸环化酶的协调激活。
Progesterone appears to be the physiological inducer of the resumption of the meiotic divisions in amphibian oocytes. Within minutes following exposure to progesterone there is a release of Ca2+and a transient rise in [cAMP]ifollowed by a fall in [cAMP]iand rise in [cGMP]iover the next 1–3 h. Agents that induce a fall in [cAMP]iinduce meiosis whereas those that prevent the fall and/or elevate [cAMP]iblock meiosis. A comparison of the conversion of injected [3H]-ATP to [3H]-cAMP and rate of hydrolysis of injected [3H]-cAMP following exposure to meiotic agonists and antagonists indicates that adenylate cyclase and not phosphodiesterase is the rate-limiting step in regulating [cAMP]iin the oocyte. These findings are consistent with a model in which progesterone initiates the resumption of the meiotic divisions by down-regulation of membrane adenylate cyclase via Ca2+release from specific membrane sites and that a translocation of Ca2+produces a coordinate activation of guanylate cyclase.