Gómez M C, Catt J W, Evans G, Maxwell W M
Department of Animal Science, University of Sydney, NSW, Australia.
Reprod Fertil Dev. 1998;10(2):197-205. doi: 10.1071/r98002.
The effect of calcium concentration on fertilization and activation was examined in oocytes injected in vitro with sperm. Oocytes were subjected to sperm injection, to sham injection or remained uninjected, and were then cultured for 19 h in bicarbonate-buffered synthetic oviduct fluid (BSOF) without calcium, or containing either calcium chloride or calcium ionophore. There was no difference in fertilization rates after ICSI when oocytes were cultured in vitro in media containing calcium chloride or calcium ionophore but the rate was lower in calcium-free media. There was also no difference in the fertilization rate after ICSI when oocytes were cultured in vivo compared with that observed in vitro in media containing calcium chloride or calcium ionophore. In calcium chloride-treated oocytes, activation was induced by mechanical injection, and in calcium ionophore-treated oocytes, by the ionophore. In uninjected oocytes, calcium itself did not cause oocyte activation. It is concluded that it is possible to induce activation by the injection process, but that manipulation alone is inadequate to cause proper oocyte activation unless calcium is also present. No difference in oocyte activation between ICSI and sham injection was found, indicating that the sperm may play no role in the early events of oocyte activation.
在体外向卵母细胞注射精子后，研究了钙浓度对受精和激活的影响。对卵母细胞进行精子注射、假注射或不进行注射，然后在不含钙、含有氯化钙或钙离子载体的碳酸氢盐缓冲合成输卵管液（BSOF）中培养19小时。当卵母细胞在含有氯化钙或钙离子载体的培养基中体外培养时，卵胞浆内单精子注射（ICSI）后的受精率没有差异，但在无钙培养基中受精率较低。与在含有氯化钙或钙离子载体的培养基中体外培养的情况相比，卵母细胞体内培养后ICSI的受精率也没有差异。在氯化钙处理的卵母细胞中，通过机械注射诱导激活，在钙离子载体处理的卵母细胞中，通过离子载体诱导激活。在未注射的卵母细胞中，钙本身不会引起卵母细胞激活。得出的结论是，通过注射过程有可能诱导激活，但除非也存在钙，否则仅通过操作不足以引起适当的卵母细胞激活。在ICSI和假注射之间未发现卵母细胞激活的差异，表明精子可能在卵母细胞激活的早期事件中不起作用。
