Biphasic effect of GABA on rat sperm acrosome reaction:: Involvement of GABAA and GABAB receptors
Biphasic effect of GABA on rat sperm acrosome reaction:: Involvement of GABAA and GABAB receptors
复制标题
DOI：
10.1080/01485010290099246
复制
发表时间：
2002-09-01
期刊：
影响因子：
--
通讯作者：
Yan, YC
中科院分区：
文献类型：
--
作者：
Hu, JH;He, XB;Yan, YC
通过研究GABA（B）受体激动剂和拮抗剂对大鼠精子气体反应（AR）的不同影响，证实了GABA（A）和GABA（B）受体在调节AR中的功能关系。使用金霉素染色测定AR率。GABA对大鼠精子AR的诱导是一个双相现象，AR率随着GABA浓度的增加而增加（尖端至5 μ M），AR率降低。这种双相现象显然是由于神经递质与GABA受体亚型以剂量依赖性方式的差异相互作用;即，GABA（A）受体（刺激性）主要在低浓度GABA下被激活，而GABA（B）受体（抑制性）在较高浓度下被激活。这一假设得到了以下结果的支持：用GABA（B）受体拮抗剂萨氯芬处理，在低浓度下不影响GABA引起的AR率，而在高浓度下，AR率维持在最大水平，从而消除了双相现象。巴氯芬是一种GABA（B）受体激动剂，在低浓度和高浓度下均可阻断GABA的AR激活作用。GABA对大鼠精子AR的诱导似乎受激活的GABA（A）和GABA（B）受体比例的调节，这两种受体作为阴阳对照。
The functional relationship between GABA(A) and GABA(B) receptors in regulating aerosome reaction (AR) of rat spermatozoa was demonstrated by studying the differential effects of a GABA(B) agonist and an antagonist on the process. AR rates were determined using the chlortetracycline staining assay. The induction of AR in rat sperm by GABA Was found to be a biphasic phenomenon i.e., AR rates increased with increasing GABA concentrations tip to 5 muM), there was a reduction in the AR rates. This biphasic phenomenon is apparently due to the differential interaction of the neurotransmitter with GABA receptor subtypes in a dose-dependent manner; i.e., GABA(A) receptors (stimulatory) are primarily activated at low concentration of GABA, while GABA(B) receptors (inhibitory) become activated at higher concentrations. This hypothesis is supported by the present findings that treatment with saclofen, a GABA(B) receptor antagonist, did not influence the AR rates effected by GABA at low concentrations; while the A R rates were maintained at the maximum level at higher concentrations of GABA, resulting in the elimination of the biphasic phenomenon. Baclofen, a GABA(B) receptor agonist, blocks the AR activating action of GABA at both low and high concentrations. It would appear that the induction of AR in rat sperm by GABA is regulated by the proportionality of activated GABA(A) and GABA(B) receptors acting as a yin-yang control.