Abstract:Objective To study the effect of retinoic acid (RA) on the proliferation, differentiation and meiosis of spermatogenic cells in cryptorchidism and its mechanism. Methods The offspring of male SD rats were used for the study. The normal control group did not receive any drugs or reagents, Flu cryptorchidism group was induced by androgen antagonist flutamide (Flu), RA intervention group was given retinoic acid intervention during spermatogenic cell development. The spermatogenic cell apoptosis was detected by TUNEL; the expression of Stra8, Scp3 and c-Kit protein in testis tissue was observed by immunohistochemistry; the mRNA levels of Stra8, c-Kit and PLZF in testicular tissue were detected by RT-qPCR; the expression of Stra8, Scp3, c-Kit and PLZF protein in testicular tissue was detected by Western blotting. Results Pathological examination showed that a large number of sperm cells were found in the normal control group and RA intervention group, and the germ cells in all layers were arranged regularly. However, the number of germ cells at all levels in the testis of Flu cryptorchidism group was reduced and disordered, and the lumen of seminiferous tubules was significantly narrowed. TUNEL assay showed that a large number of spermatogenic cells were apoptosis in flu cryptorchidism group compared with normal control group and RA intervention group. Compared with the flu model group, the apoptosis index of the control group and RA intervention group was lower (P < 0.05). Compared with the flu cryptorchidism group, the expression levels of Stra8, c-Kit, Scp3 mRNA and protein were higher in the control group and RA intervention group (P < 0.05). Compared with the flu cryptorchidism group, the PLZF protein expression level in the control group and RA intervention group was higher (P < 0.05). Conclusions The mechanism of retinoic acid promoting spermatogenic cell development may be related to regulating the meiotic differentiation and proliferation of cryptorchidism spermatogenic cells, which restores the reproductive function of cryptorchidism rats to a certain extent.