Ghrelin modulates testicular germ cells apoptosis and proliferation in adult normal rats

► Spermatogenesis is closely associated with the balance between germ cells proliferation and apoptosis. ► Numerous studies have documented the direct action of ghrelin in the modulation of apoptosis in different cell types. ► Ghrelin may be considered as a modulator of spermatogenesis in normal adult rats. ► Ghrelin may be potentially implicated for abnormal spermatogenesis in some testicular germ cell tumors. Under normal condition in the most mammals, spermatogenesis is closely associated with the balance between germ cells proliferation and apoptosis. The present study was designed to determine the effects of ghrelin treatment on in vivo quality and quantity expression of apoptosis and proliferation specific indices in rat testicular germ cells. Twenty eight adult normal rats were subdivided into equal control and treatment groups. Treatment group received 3nmol of ghrelin as subcutaneous injection for 30 consecutive days or vehicle to the control animals. The rats from each group (n=7) were killed on days 10 and 30 and their testes were taken for immunocytochemical evaluation and caspase-3 assay. Immunohistochemical analysis indicated that the accumulations of Bax and PCNA peptides are generally more prominent in spermatocytes and spermatogonia of both groups. Likewise, the mean percentage of immunoreactive spermatocytes against Bax increased (P