Fröhlich H, Kugler P, Schiebler T H
Z Mikrosk Anat Forsch. 1984;98(1):86-106.
Protein excretion and protein fractions according to their molecular weight (SDS polyacrylamide-gelectrophoresis) were studied in the urine of male and female rats before and after castration. The polyacrylamide-gels were investigated qualitatively as well as quantitatively by densitometry. Male rats excrete considerably more protein in the urine than female rats. The values for the absolute protein quantity in 24-h-urine and the relative proteinuria (mg protein per 24 h and 100 g body weight) are five and three times higher, respectively, in males than in females. After castration proteinuria decreases significantly in both sexes, in males, however, more considerably (by about 75%) than in females (by about 30%), so that there is no significant difference in relative proteinuria between castrated males and females. The electrophoresis method used in this study allows to distinguish at least 10 to 11 protein fractions in the total urinary protein of both sexes within a molecular weight range from about 94.000 d to 14.000 d. Low molecular weight proteins (about 31.000 d to about 14.000 d) represent in both sexes the main part of the urinary protein. Females, however, excrete relatively more high molecular weight proteins (about 94.000 d to 60.000 d; about 25% of total urinary protein) than males (about 15% of total urinary protein). Concerning the relative parts in total urinary protein there are sex differences in all protein fractions, especially, however, in the fraction with a molecular weight of about 19.000 d (males more than 50%, females about 17% of total urinary protein). Castration causes in males more distinct changes in the relative parts of protein fractions in total urinary protein (drastic decrease of the 19.000-d-fraction) than in females. The results can be interpreted among other things in connection with a sex different handling of proteins in the proximal tubule of the rat kidney. The lysosomal catabolism of proteins in the proximal tubule is probably lower in males than in females, thus contributing to a higher proteinuria and a higher excretion especially of low molecular weight proteins in males in comparison with females.
对阉割前后雄性和雌性大鼠尿液中的蛋白质排泄及按分子量划分的蛋白质组分（十二烷基硫酸钠 - 聚丙烯酰胺凝胶电泳）进行了研究。通过光密度测定法对聚丙烯酰胺凝胶进行了定性和定量研究。雄性大鼠尿液中排出的蛋白质比雌性大鼠多得多。24小时尿液中绝对蛋白量以及相对蛋白尿（每24小时和每100克体重的蛋白毫克数）的值，雄性分别比雌性高五倍和三倍。阉割后，两性的蛋白尿均显著降低，然而，雄性降低得更明显（约75%），雌性降低约30%，因此阉割后的雄性和雌性在相对蛋白尿方面没有显著差异。本研究中使用的电泳方法能够在分子量范围约94,000道尔顿至14,000道尔顿内区分两性总尿蛋白中至少10至11种蛋白质组分。低分子量蛋白质（约31,000道尔顿至约14,000道尔顿）在两性中均占尿蛋白的主要部分。然而，雌性排泄的相对高分子量蛋白质（约94,000道尔顿至60,000道尔顿；约占总尿蛋白的25%）比雄性（约占总尿蛋白的15%）多。关于总尿蛋白中的相对比例，所有蛋白质组分都存在性别差异，尤其是分子量约为19,000道尔顿的组分（雄性超过总尿蛋白的50%，雌性约为17%）。阉割导致雄性总尿蛋白中蛋白质组分的相对比例变化比雌性更明显（19,000道尔顿组分急剧下降）。这些结果除其他外，可以与大鼠肾脏近端小管中蛋白质的性别差异处理联系起来解释。雄性近端小管中蛋白质的溶酶体分解代谢可能低于雌性，因此与雌性相比，雄性蛋白尿更高，尤其是低分子量蛋白质的排泄更高。
