The effect of induced anti-follicle-stimulating hormone autoantibody on serum hormone level and apoptosis in rat testis.

Aims: Anti-follicle-stimulating hormone (FSH) autoantibody was found to highly correlate with oligospermia and asthenospermia, but the actual effect of FSH autoantibody on spermatogenesis is still unknown.

Main Methods: In this study, 21-day rats were immunized seven times with FSH peptides linked with Keyhole Limpet Hemocyanin (KLH) (experimental group) or KLH (control group) every 2 weeks. Luteinizing hormone (LH) and inhibin B level in the immunized rat sera were measured by enzyme-linked immunosorbent assay (ELISA). Apoptosis of spermatogenic cells in the testis was detected by in situ end labeling method (TUNEL), and the mRNAs of Bax, Bcl-2 and Caspase-3 in testis were detected by fluorescent Quantitative PCR.

Key Findings: Compared with the control, serum inhibin B level was significantly decreased at all time points (34.49%, 23.20%, and 37.00%) (p<0.05). There was no difference in the serum LH level between experimental and control groups. FSH peptide immunization increased the apoptosis of spermatogenic cells in the testis that was associated with an imbalance of Bax and Bcl-2 expression and upregulation of Caspase-3.

Significance: These results suggest that FSH autoantibody could cause the reduction of inhibin B, thereby inducing hypospermatogenesis via augment of spermatogenic cell apoptosis.