A Study of sperm fertilizing ability and intracellular calcium.

1. 据报道，黄体酮、前列腺素和卵泡液通过细胞外钙流入人精子的细胞质而增强顶体反应。前列腺素存在于男性生殖道内，精液中也有高浓度的前列腺素。为了探讨前列腺素通过钙内流增强顶体反应的机制，我们用fura-2测定了孕酮、前列腺素、前列腺素2和卵泡液诱导的细胞内钙反应。前列腺素和前列腺素2通过二氢吡啶不敏感钙通道剂量依赖性地促进钙内流。当前列腺素6mg /ml或黄体酮1mg /ml给药100秒后，细胞内钙浓度（[Ca^2^+]i）对第二次刺激的升高不耐。当前列腺素浓度为6mg /ml时，也出现了不耐现象，但在前列腺素和孕酮之间没有出现不耐现象。添加前列腺素el或前列腺素ine2后，百日咳毒素（PTX）未改变[Ca^2^+]i的变化。总之，前列腺素和前列腺素2促进钙通过ptx不敏感的钙通道内流，这似乎是由一种不同于黄体酮的共同受体识别的。卵泡液或黄体酮诱导的[Ca^2^+]i升高可促进人精子顶体反应。我们以前报道过，通过细胞悬浮法，来自形态异常的不育男性的精子显示出比形态正常精子更低的黄体酮诱发[Ca^2^+]i的平均峰值。本研究比较了人卵泡液诱导的[Ca^2^+]i在个体正常和异常形态精子中的变化。正常形态精子的[Ca^2^+]i在给予人卵泡液后迅速增加。反应在2-3秒内达到峰值，然后缓慢下降到平稳期。与正常精子相比，形态异常精子的基线和峰值荧光较低。卵泡液诱导的[Ca^2^+]i升高（以[Ca^2^+]i在基底上的升高百分比表示）为7.1*6.4%(n=22)，小于正常精子的20.5*24.0% （n= 46）。p < 0.05)。此外，还研究了[Ca^2^+]i在单精子中增加的空间分布。[Ca^2^+]i仅在精子头部升高，精子尾部未见[Ca^2^+]i升高。本研究提出了形态异常的精子可能存在信号转导紊乱导致顶体反应受损，从而导致不育的可能性。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