Calcium-dependent increase in adenosine 3',5'-monophosphate and induction of the acrosome reaction in guinea pig spermatozoa.
Calcium-dependent increase in adenosine 3',5'-monophosphate and induction of the acrosome reaction in guinea pig spermatozoa.
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豚鼠精子中 3,5-单磷酸腺苷的钙依赖性增加和顶体反应的诱导。
DOI：
10.1073/pnas.76.11.5699
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发表时间：
1979
影响因子：
11.1
通讯作者：
D. Garbers
中科院分区：
文献类型：
--
作者：
R. Hyne;D. Garbers
本实验旨在研究精子获能和顶体反应过程中cAMP和Ca（2+）的相互关系。在含有丙酮酸盐和乳酸盐作为底物的基本培养基中，豚鼠精子在1.7 mM Ca（2+）存在下至少需要1.0-1.5 h才能获能，在不添加Ca（2+）的情况下至少需要0.5-1.0 h才能获能。将精子细胞加入到各种含Ca（2+）的培养基中后，精子环AMP浓度在0.5分钟内增加了30倍，然后浓度保持增加长达4小时。环AMP浓度在0.5分钟内仅增加约3倍，然后在2分钟内恢复到基础浓度。D-600，一种钙转运拮抗剂，完全阻断Ca（2+）诱导的精子cAMP浓度升高。与获能相反，在细胞外Ca（2+）缺乏的情况下，顶体反应未能发生。在无Ca（2+）的培养液中，精子获能后，加入Ca（2+）可在1 min内引起精子cAMP浓度的增加，并在10 min内引起最大数量的精子出现顶体反应。加入1-甲基-3-异丁基黄嘌呤沿着加入Ca（2+）对cAMP的增加有协同作用。1-甲基-3-异丁基黄嘌呤和8-溴环磷酸腺苷在无Ca（2+）的情况下均不能诱导获能精子的顶体反应，但在有Ca（2+）的情况下，两者均能显著缩短顶体反应达到最大表达所需的时间。这些结果表明，精子顶体反应与Ca（2+）的初级运输和精子cAMP浓度的Ca（2+）依赖性增加有关。由于在不加Ca（2+）的情况下，环AMP类似物不诱导顶体反应，因此Ca（2+）诱导的精子环AMP浓度增加可能反映了与顶体反应相关的许多Ca（2+）依赖性事件之一。
Experiments were designed to determine the interrelationship between cyclic AMP and Ca(2+) during the processes of sperm capacitation and the acrosome reaction. In minimal culture media containing pyruvate and lactate as substrates, guinea pig spermatozoa required a minimum of 1.0-1.5 hr to capacitate in the presence of 1.7 mM Ca(2+) and a minimum of 0.5-1.0 hr to capacitate in the absence of added Ca(2+). Sperm cyclic AMP concentrations were increased by as much as 30-fold within 0.5 min after addition of cells to various media containing Ca(2+), and the concentrations then remained increased for up to 4 hr. When the cells were added to several Ca(2+)-deficient media, however, cyclic AMP concentrations increased only about 3-fold within 0.5 min and then returned to basal concentrations within 2 min. D-600, a calcium transport antagonist, completely blocked the Ca(2+)-induced increase in sperm cyclic AMP concentrations. In contrast to capacitation, the acrosome reaction failed to occur in the absence of extracellular Ca(2+). After capacitation of spermatozoa in a Ca(2+)-free medium, addition of Ca(2+) caused an increase in sperm cyclic AMP concentrations within 1 min and a maximal number of spermatozoa showing an acrosome reaction within 10 min. The addition of 1-methyl-3-isobutylxanthine along with Ca(2+) had a synergistic effect on the increase in cyclic AMP. Neither 1-methyl-3-isobutylxanthine nor 8-Br cyclic AMP induced an acrosome reaction in capacitated spermatozoa in the absence of Ca(2+), but both significantly decreased the time required for maximal expression of the acrosome reaction in the presence of Ca(2+). These results suggest that the sperm acrosome reaction is associated with both a primary transport of Ca(2+) and a Ca(2+)-dependent increase in sperm cyclic AMP concentrations. Because a cyclic AMP analogue did not induce an acrosome reaction in the absence of added Ca(2+), the increase in sperm cyclic AMP concentrations induced by Ca(2+) probably reflects one of a number of Ca(2+)-dependent events associated with the acrosome reaction.