哺乳动物的睾丸是由解剖上完全不同的两种腔隙组织紧密结合在一起所组成。在里面的非血管区是参与产生精原细胞或精子的曲细精管,在外面的有丰富血管区含有产生雄激素的间质细胞。雄激素由间质液输送至曲细精管,并通过睾丸液输送至副睾内,或回流至静脉进入体循环,雄激素在曲细精管和副睾内存留,依靠在其管腔内含有结合蛋白。Hansson Ri-tyen及French的研究指出,在许多种属的睾 Mammalian testes are composed of two anatomically distinct lacunar tissues that are tightly bound together. The non-vascular zone inside is a seminiferous tubule that participates in the production of spermatogonia or spermatozoa. On the outside there is a plentiful vascular area that contains androgen-producing mesenchymal cells. Androgen is delivered to the seminiferous tubules by the interstitial fluid and is delivered to the epididymis by the testicular fluid or back into the vein into the systemic circulation. The androgen resides in the seminiferous tubules and the epididymis, Binding protein. Studies by Hansson Ri-tyen and French indicate that in many species of testis