实验性精索静脉曲张大鼠附睾分泌蛋白的鉴定研究

目的　研究精索静脉曲张对附睾合成与分泌蛋白的影响 ,鉴定病理状况下附睾特异改变的蛋白成分。　方法　部分结扎左肾静脉建立实验性左侧精索静脉曲张大鼠动物模型。用 SDS-PAGE和双向电泳分离左附睾尾匀浆上清中的蛋白质组分 ,切下稳定出现改变的蛋白质所在的条带或斑点 ,进行胶内胰蛋白酶消化 ,酶解得到的最终肽混合物进行肽质量指纹谱测定。通过检索互联网上的蛋白质数据库确定该蛋白的可能成分。　结果　与对照动物相比 ,实验性左侧精索静脉曲张大鼠左附睾尾匀浆上清中一分子量约2 0× 1 0 3、等电点约 5.5的蛋白成分明显增加。经质谱分析结合网上数据库检索表明 ,该蛋白是附睾视黄酸结合蛋白。　结论　实验性左侧精索静脉曲张导致大鼠附睾中视黄酸结合蛋白含量升高 ,这一改变对精子在附睾中成熟及精子功能的影响有待进一步研究

Identification and characterization of the epididymal secretive protein from experimental varicocele rats

Objective: To identify the specific changes of epididymal secretive proteins from experimental rats, aiming to illuminate the effect of varicocele on epididymis and sperm maturation. Methods: Experimental left varicocele model of SD rats were obtained by partial ligation of left renal vein. The SDS PAGE and two dimensional electrophoresis were used to separate the proteins in the supernatants of homogenates from the left cauda epididymides. The novel protein bands or spots were cut off, followed by in gel trypsin digestion. The digested protein was analyzed by peptide mass fingerprinting (PMF) and protein database searching on internet. Results: A protein with the MW 20 KD, pI 5.5 was markedly up expressed in the animal with experimental left varicocele compared with that in sham operated group. PMF and the internet searching of protein database reveal it as the epididymal retinoic acid binding protein(ERBP). Conclusion: The epididymal retinoic acid binding protein was up expressed in the epididymal secretive components of experimental left varicocele SD rats, which may be one of the manifestations of epididymis malnutrition. Whether or not the measurement of the epididymal retinoic acid binding protein in the secretive component of epididymal duct helps to determine the functional state of epididymis and sperm maturation requires further research.