Redistribution of a rat sperm epididymal glycoprotein after in vitro and in vivo capacitation
Redistribution of a rat sperm epididymal glycoprotein after in vitro and in vivo capacitation
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体外和体内获能后大鼠精子附睾糖蛋白的重新分布
DOI：
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发表时间：
1992
影响因子：
2.5
通讯作者：
P. Cuasnicú
中科院分区：
文献类型：
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作者：
L. Rochwerger;P. Cuasnicú
大鼠附睾糖蛋白DE （37kDa）在精子成熟过程中与精子表面有关，位于顶体背侧区域。在本研究中，我们通过间接免疫荧光检测体外和体内容能后DE的定位。49%的精子在体外激活5小时后仍在精子背侧区域出现荧光，51%的精子在精子头部赤道段对应的区域出现标记。这种荧光定位的变化与精子退化或死亡无关，并随获能时间逐渐增加，在5小时时达到最大值。赤道段上标记的存在是由于蛋白质迁移造成的，不能通过渗透、蛋白酶或高离子强度处理来诱导。标准容能培养基中Ca2+的缺失抑制了DE的再定位，用Ca2+离子载体A23187孵育诱导顶体反应（AR）显著提高了DE定位在赤道地区的细胞百分比。最后，从体内受精卵的输卵管中恢复的自由精子和积云相关精子分别占再分布细胞的15%和21%，而所有卵泡周围（顶体反应）精子在赤道段均显示DE。这些结果表明，在体外和体内条件下，附睾蛋白DE迁移到赤道段，并提示DE的重新分布与AR的发生之间可能存在关联。
Rat epididymal glycoprotein DE (37kDa) associates with the sperm surface during maturation and is localized over the dorsal region of the acrosome. In the present study we examine, by indirect immunofluorescence, the localization of DE after in virto and in vivo capacitation. While 49% of sperm capacitated in vitro for 5 hr still presented fluorescence over the dorsal region, 51% showed labeling distributed over a domain that corresponds to the equatorial segment of the sperm head. This change in the localization of fluorescence was not associated with sperm deterioration or death and increased gradually as a function of capacitation time, reaching the maximum at 5 hr. The presence of labeling over the equatorial segment results from protein migration and cannot be induced by permeabilization, proteinase, or high ionic strength treatments. The omission of Ca2+ from the standard capacitation medium inhibitied the relocalization of DE, and incubation with Ca2+ ionophore A23187 for induction of the acrosome reaction (AR) significantly raised the percentage of cells with DE localized over the equatorial region. Finally, while free and cumulus‐associated spermatozoa recovered from the oviducts of in vivo inseminated females presented 15% and 21% of cells with redistribution respectively, all perivitelline (acrosome reacted) spermatozoa showed DE over the equatorial segment. These results indicate that epididymal protein DE migrates to the equatorial segment under in vitro and in vivo capacitating conditions and suggest a possible association between the redistribution of DE and the occurrence of the AR.