人类精浆的钙缓冲能力：乙二醇双四乙酸在刺激精子活力中的作用

Calcium buffering capacity of human seminal plasma: the role of EGTA in stimulating sperm motility.

作者信息

Fong J C, Lin C H, Wei Y H, Ho L T, Hong C Y

出版信息

Chin J Physiol. 1986;29(1):7-12.

Abstract

The role of EGTA in stimulating human sperm motility (reported in Lancet i: 460-461, 1984) was investigated by measuring the calcium buffering capacity of human seminal plasma. Human seminal plasma contains 9.5 +/- 1.1 mM (mean +/- SE) calcium of which 0.16 +/- 0.01 mM only exists as free Ca2+. The free Ca2+ concentration was not changed by the addition of either 1 mM CaCl2 or 1 mM EGTA. The ability of seminal plasma to bind calcium ions was determined by adding varying amounts of CaCl2. Scatchard analysis of the results indicates the presence of high amounts of high-affinity (Kd1 = 3.4 +/- 0.2 microM, Bm1 = 11.5 +/- 1.5 mM) and low-affinity (Kd2 = 0.55 +/- 0.04 mM, Bm2 = 30.4 +/- 1.7 mM) Ca2+-complexing agents. The low-affinity Ca2+-binding substance may be citrate. These results seem to suggest that human seminal plasma has a high Ca2+ buffering capacity and the stimulation of sperm motility by EGTA ought to be mediated via a mechanism other than the reduction of the free calcium concentration in semen.

摘要

通过测量人类精浆的钙缓冲能力，研究了乙二醇双四乙酸（EGTA）对人类精子活力的刺激作用（见《柳叶刀》i：460 - 461，1984年）。人类精浆含有9.5±1.1 mM（平均值±标准误）的钙，其中仅0.16±0.01 mM以游离Ca2+形式存在。添加1 mM氯化钙或1 mM乙二醇双四乙酸（EGTA）后，游离Ca2+浓度未发生变化。通过添加不同量的氯化钙来测定精浆结合钙离子的能力。对结果进行Scatchard分析表明，存在大量高亲和力（Kd1 = 3.4±0.2 microM，Bm1 = 11.5±1.5 mM）和低亲和力（Kd2 = 0.55±0.04 mM，Bm2 = 30.4±1.7 mM）的Ca2+络合剂。低亲和力的Ca2+结合物质可能是柠檬酸盐。这些结果似乎表明，人类精浆具有较高的Ca2+缓冲能力，乙二醇双四乙酸（EGTA）对精子活力的刺激应该是通过精液中游离钙浓度降低以外的其他机制介导的。