EPIDIDYMAL GLUTATHIONE--PHYSIOLOGIC & MOLECULAR STUDIES

当精子沿着附睾管前进时，它们沐浴在 专门的腔内液体微环境，这对他们的 成熟和生存。随着精子的成熟，它们需要持续不断的 防止氧化损伤和药物的有害影响 有毒化学物质。精子受损可能会导致后代畸形。在……里面 许多组织，如肺和肾脏，谷胱甘肽(Glu-Cys-Gly) 已被证明在抗氧化防御中起着重要作用，而且似乎 很可能它在附睾处也起着类似的作用。这件事的重点是 建议是确定鲁米那谷胱甘肽 受附睾上皮的调节。我们将使用体内显微穿刺术 和微灌注技术来确定谷胱甘肽的来源 附睾部不同部位的管腔积液。我们将确定 γ-谷氨酰转肽酶(GGT)的活性，这是唯一已知的 能裂解谷胱甘肽生成谷氨酸和半胱氨酸二肽- 甘氨酸。还将进行实验以确定催化剂 将半胱氨酸-甘氨酸分解为其组成成分的二肽酶活性 氨基酸。GGT可转运半胱氨酸和甘氨酸的假说 从管腔进入附睾细胞将进行检测。我们有 先前发现，管腔GGT的催化活性从上限下降到 尾巴。因此，将设计实验来确定 附睾尾GGT活性丧失的机制(S) 区域，无论是由于酶的降解和/或 位于腔内液和/或根尖上的内切糖苷酶 尾状上皮细胞表面。使用分子生物学技术 我们将鉴定表达GGT mRNA的附睾细胞类型(S)。因此， 我们将确定那些在调控中发挥重要作用的细胞 附睾液中的谷胱甘肽。重要的是我们要了解 附睾体维持环境的机制 保护精子免受氧化和各种因素的有害影响 药物和外源生物；氧化防御对人类生存至关重要 精子。这项建议是理解以下长期目标的一部分 附睾管维持最佳管腔的机制 精子成熟和存活的微环境。由此得出的结论是 建议书还将为制定 男性避孕和某些形式的男性不育症的治疗。

As spermatozoa progress along the epididymal duct, they are bathed in a specialized luminal fluid microenvironment which is crucial for their maturation and survival. As the spermatozoa mature, they need constant protection against oxidative damage and from harmful effects of drugs and toxic chemicals. Damaged spermatozoa may lead to abnormal offspring. In many tissues such as the lung and kidney, glutathione (glu-cys-gly) has been shown to play an important role in antioxidant defense, and it seems likely that it plays a similar role in the epididymis. The focus of this proposal is to determine the manner by which luminal glutathione is regulated by the epididymal epithelium. We will use in vivo micropuncture and microperfusion techniques to determine the origin of glutathione in the luminal fluid of different epididymal regions. We will determine the activity of gamma-glutamyl transpeptidase (GGT), the only known enzyme that can cleave glutathione to yield glutamate and the dipeptide cysteine- glycine. Experiments will also be performed to determine the catalytic activity of dipeptidase which cleaves cysteine-glycine into its constituent amino acids. The hypothesis that GGT can transport cysteine and glycine from the lumen into the epididymal cells will be tested. We have previously found that luminal GGT catalytic activity declines from caput to cauda. Therefore, experiments will be designed to determine the mechanism(s) of the loss of GGT activity within the cauda epididymal region, whether it is due to degradation of the enzyme by proteases and/or endoglycosidases located within the luminal fluid and/or on the apical surface of cauda epithelial cells. Using molecular biological techniques we will identify the epididymal cell type(s) that express GGT mRNA. Hence, we will identify those cells that play an important role in the regulation of epididymal glutathione. It is critical that we understand the mechanisms by which the epididymis maintains an environment that will protect spermatozoa from oxidation and from harmful effects of various drugs and xenobiotics; oxidative defense is crucial for the survival of spermatozoa. This proposal is part of a long term goal to understand the mechanisms by which the epididymis maintains an optimal luminal microenvironment for sperm maturation and survival. The findings from this proposal will also provide fundamental information for the development of a male contraceptive and treatment of certain forms of male infertility.