Endocrine Abstracts

Cimetidine, an antagonist of histamine H2-receptors used for treatment of gastric ulcers, exerts antiandrogenic effect. In testes, cimetidine causes histopathological disorders in the seminiferous tubules and impairs spermatogenesis. Additionally to testosterone, Leydig cells (LC) produce several paracrine factors, including EG–VEGF (endocrine gland-derived vascular endothelial growth factor) which participates in the testicular microvasculature control. Regarding the imp...

In vertebrates, ARs have been detected in spermatogonia and also fetal gonocytes, confirming the importance of testosterone for the initial process of spermatogenesis. During seasonal spermatogenesis of adult bullfrogs (Lithobates catesbeianus), primordial germ (PG) cells show testosterone immunoexpression in winter; however, a weak or none testosterone immunoexpression was detected in summer. With the aim to confirm the role of testosterone in these cells, the immunogold loca...