A Study of sperm fertilizing ability and intracellular calcium.

1.黄体酮、前列腺素和卵泡液被报道通过细胞外钙内流到精子细胞质来增强顶体反应。前列腺素存在于男性生殖道内，精液中存在高浓度的前列腺素，为了探讨前列腺素通过钙内流促进顶体反应的机制，用Fura-2测定了孕酮、前列腺素E_1、前列腺素E_2和卵泡液诱导的细胞内钙反应。前列腺素E_1和前列腺素E_2通过二氢吡啶不敏感的钙通道促进钙内流，并呈剂量依赖性。前列腺素E_1浓度为60mug/ml或孕酮浓度为1mug/ml时，细胞内钙离子浓度([Ca^2~+]i)的升高对第二次刺激无效。60mug/ml前列腺素EL给药…时也出现了难治性加入前列腺素E_2 60mug/ml后，作用时间延长，但在前列腺素E_1和孕酮之间未见明显变化。百日咳毒素(PTX)不改变加入前列腺素E_1或前列腺素E_2后[Ca~(2+)]i的变化。总之，前列腺素E_1和前列腺素E_2通过PTX不敏感的钙通道促进钙内流，这种钙通道似乎是由与孕酮不同的共同受体识别的。卵泡液或黄体酮引起的[Ca^2+]i升高促进人精子顶体反应。我们以前曾报道，形态异常的不育男性精子在细胞悬浮法中孕酮诱发的[Ca^2+]i平均峰值低于形态正常的精子。本研究比较了人卵泡液对正常和畸形精子[Ca~(2+)]i的影响。正常形态精子经人卵泡液处理后，[Ca^2+]i迅速升高。反应在2-3秒内达到峰值，然后缓慢下降到平台期。形态异常精子的基线荧光和峰值荧光均低于正常精子。卵泡液引起的[Ca^2+]i升高(以[Ca^2+]i较基础值增加的百分比表示)在畸形精子组为7.1×6.4%(n=22)，低于正常形态精子组(20.5×24.0%，n=46)。P&lt；0.05)。此外，还研究了单个精子内[Ca^2+]i升高的空间分布。[Ca^2+]i仅在精子头部升高，而在精子尾部未见升高。这项研究提出，形态异常的精子存在信号转导障碍，导致顶体反应受损，从而导致不育的可能性。较少

1. Progesterone, prostaglandin and follicular fluid are reported to enhance the acrosome reaction through the influx of extracellular calcium into the cytoplasm of human spermatozoa. Prostaglandins are present within the male reproductive tract, and high concentrations of prostaglandins exist in seminal fluid, In order to investigate the mechanisms by which prostaglandins enhance the acrosome reaction through calcium influx, the intracellular calcium response induced by progesterone, prostaglandinEl, prostaglandinE2 and follicular fluid was measured using fura-2. ProstaglandinEl and prostaglandinE2 promoted calcium influx dose dependently through dihydropyridine insensitive calcium channels. Refractoriness of the elevation of intracellular Ca concentration ([Ca^2^+]i) to a second stimulus occurred when 6Omug/ml prostaglandinEl or 1mug/ml progesterone was administrated 100 seconds after the prior administration. Refractoriness also occurred when 6Omug/ml prostaglandinEl was administrate … More d after the prior addition of 6Omug/ml prostaglandinE2, but did not occur between prostaglandinEl and progesterone. Pertussis toxin(PTX) did not modify the changes in [Ca^2^+]i after the addition of prostaglandinEl or prostaglandinE2. In conclusion, prostaglandinEl and prostaglandinE2 promoted calcium influx through PTX-insensitive calcium channels which appeared to be recognized by a common receptor different from that of progesterone.2. The increase of [Ca^2^+]i induced by follicular fluid or progesterone promotes an acrosome reaction in human sperm. We previously reported that sperm from infertile men with abnormal morphology exhibited lower mean peak progesterone-evoked [Ca^2^+]i than morphologically normal sperm by cell-suspension methods. In this study, the change of [Ca^2^+]i induced by human follicular fluid in individual normally and abnormally shaped spermatozoa was compared. [Ca^2^+]i of normally shaped spermatozoa increased rapidly after the administration of human follicular fluid. The response reached a peak within 2-3 seconds and then slowly declined to the plateau phase. The fluorescence of baseline and peak of the spermatozoa with abnormal morphology was lower when compared with normal sperm. Follicular fluid-induced [Ca^2^+]i increase (expressed as percent increase of [Ca^2^+]i over basal) in abnormal shaped sperm was 7.1*6.4%(n=22), smaller than that of normally shaped sperm(20.5*24.0%, n=46. p<0.05). Moreover, the spatial distribution of the increase of [Ca^2^+]i in single sperm was investigated. The increase in [Ca^2^+]i was observed only in the head of spermatozoon, and there was no [Ca^2^+]i increase in the sperm tail. This study raises the possibility that spermatozoa with abnormal morphology have disorders of signal transduction leading to an impaired acrosome reaction, which result in infertility. Less