Evidence for the presence of angiogenin in human testis

We have reported the expression and possible roles of angiogenin, a potent angiogenic factor, in human female reproductive organs. In this study, we investigated the expression of angiogenin in the human testis, a male reproductive organ. Western blot analysis showed the presence of angiogenin in the human testis, with a single band of the same size as recombinant human angiogenin. Immunohistochemical study and in situ hybridization showed that the angiogenin protein and messenger RNA (mRNA) localized in peritubular myoid cells (PTMCs) and vascular endothelial and smooth muscle cells. PTMCs are known to play various roles in the testes concerned with spermatogenesis, transport of spermatozoa, structural support to the seminiferous tubules, and mediation of Sertoli cell function. The specific localization of angiogenin in PTMCs suggests that angiogenin plays physiologic roles in the human testis.