腺嘌呤核苷脱氨酶及核苷运转系统对精子运动的调节作用

 腺嘌呤核苷(ADO)和它的类似物2-Cl-ADO对牛附睾尾部精子的运动有刺激作用,为了探讨ADO及其类似物对精子运动调节作用的机理,我们从ADO受体,核苷运转系统(NTS)及腺苷脱氨酶(ADA)三个方面对牛附睾尾部的精子进行了研究。我们发现腺苷受体不存在于牛精子膜上,但ADA和NTS以膜蛋白的形式结合在精子膜上,并对精子体内的ADO浓度起调节作用。我们的结论是ADO及其类似物对牛精子运动的调节作用是首先通过精子膜上的ADA和NTS影响精子体内的ADO浓度,进而ADO又通过调节钙离子浓度刺激牛精子运动。

Adenosine Deaminase and Nucleoside Transport System Effect on the Motilty of Bovine caudal Spermatozoa

It has been reported that adenosine and its analogues can elevate the concentration of intracellular cyclic AMP in bovine caudal sperm and stimulate its moti lity of sperm. In order to investigate the mechanism of this action, the present study has been concentrated on the aspect of adenosine receptor, adenosine deaminase(ADA) and nucleoside transport system (NTS).We have found that the receptor is not involved in the mechanism because theophilline, the receptor's antagonist, dose not effect the binding of 2-Cl-adenosine to bovine caudal sperm, but the ADA and NTS are involoved in the regulation process. Both ADA and NTS can mediate the level of the intrasperm adenosine which then affect the activity of both adenylate cyclase and cAMP phosphodiesterase through the regulation of intrasperm calcium level, As a result, the sperm intercellular cAMP level is increased to stimulate the motility of the sperm