Montiel E E, Huidobro C C, Castellon E A
Physiology and Biophysics Program, Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Santiago, Chile.
Arch Androl. 2003 Mar-Apr;49(2):95-105. doi: 10.1080/01485010390129296-1.
Protection of maturing sperm from potential endogenous or exogenous harmful substances during their transit throughout the epididymis is a critical event. The authors studied the activity of gamma-glutamyl transpeptidase (GGT) and glutathione S-transferase (GST), and glutathione (GSH) levels in epithelial cell cultures from human caput, corpus, and cauda epididymides. Tissue was obtained from patients undergoing therapeutic orchidectomy for prostatic cancer. Enzymatic activity was measured in conditioned media and cellular fractions. Androgen influence was also evaluated. Both enzymatic activities were found in cellular homogenates and conditioned media from cultures of all epididymal regions. GGT activity was highest in cultures from cauda epididymis, both in conditioned media and cell fractions, while GST activity did not show regional differences in conditioned media, but exhibited higher activity in cell homogenates from cauda cultures than those obtained from corpus and caput epididymis. GSH level showed no regional difference in cell homogenates and it could not be detected in conditioned media by the method used. Presence of different concentrations of dihydrotestosterone (DHT) had no influence neither on the enzymatic activities nor GSH concentration. The results indicate that GGT and GST are present along the human epididymis and a fraction or isoform of these enzymes might be secreted to the luminal fluid to play a detoxificative role in sperm maturation.
在整个附睾转运过程中保护成熟精子免受潜在的内源性或外源性有害物质的影响是一个关键事件。作者研究了来自人附睾头、体和尾的上皮细胞培养物中γ-谷氨酰转肽酶（GGT）和谷胱甘肽S-转移酶（GST）的活性以及谷胱甘肽（GSH）水平。组织取自因前列腺癌接受治疗性睾丸切除术的患者。在条件培养基和细胞组分中测量酶活性。还评估了雄激素的影响。在所有附睾区域培养物的细胞匀浆和条件培养基中均发现了这两种酶的活性。GGT活性在附睾尾培养物的条件培养基和细胞组分中均最高，而GST活性在条件培养基中未显示出区域差异，但在附睾尾培养物的细胞匀浆中比附睾体和附睾头培养物中的活性更高。GSH水平在细胞匀浆中未显示出区域差异，并且用所使用的方法在条件培养基中无法检测到。不同浓度的二氢睾酮（DHT）的存在对酶活性和GSH浓度均无影响。结果表明，GGT和GST存在于整个人附睾中，这些酶的一部分或同工型可能分泌到管腔液中，在精子成熟过程中发挥解毒作用。
