Schindler A M, Dayer A, Bischof P
Hum Reprod. 1986 Feb;1(2):55-9. doi: 10.1093/oxfordjournals.humrep.a136360.
Pregnancy-associated plasma protein-A (PAPP-A) has been found in seminal fluid at concentrations 10-20 times higher than in plasma. This observation prompted us to undertake a morphological study of the male genital tract with the aid of the immunoperoxidase technique. Immunoreactive cells were found among the Leydig cell population, as well as among the epithelium of the rete testis, the head of the epididymis and the seminal vesicles. The relatively small number of weakly staining epithelial cells leaves open the question of whether PAPP-A is excreted by these cells or whether an active transfer mechanism - possibly in the seminal vesicles - is at work, the Leydig cells increasing the plasma concentration locally, by secretion of PAPP-A into the circulation.
妊娠相关血浆蛋白-A（PAPP-A）已在精液中被发现，其浓度比血浆中的浓度高10至20倍。这一观察结果促使我们借助免疫过氧化物酶技术对男性生殖道进行形态学研究。在睾丸间质细胞群体中以及在睾丸网、附睾头部和精囊的上皮细胞中发现了免疫反应性细胞。相对少量的弱染色上皮细胞使得PAPP-A是由这些细胞分泌，还是存在一种活跃的转运机制——可能在精囊中——在起作用这一问题悬而未决，睾丸间质细胞通过将PAPP-A分泌到循环中，局部提高血浆浓度。
