Scream Sound-induced Chronic Psychological Stress Results in Diminished Ovarian Reserve in Adult Female Rat

Abstract

It is well established that chronic psychological stress (PS) induces female reproductive dysfunction. However, the studies on the consequences of chronic PS exposure precisely targeting ovarian reserve are lacking. In the present study, we employed a chronic scream sound-induced PS model to investigate the potential effect of pure psychosocial stressors on ovary reserve. Female rats were subjected to scream sound stress, white noise, or background for 3 weeks. Animals were euthanized by cervical dislocation after stress for collection of blood or ovaries. Sex hormones were analyzed by enzyme-linked immunosorbent assay. The follicle number was examined by histopathology. Granulosa cell apoptosis of the ovaries was examined by in situ cell death detection kit. Finally, rats were mated with proven fertile male rats to study fertility parameters. Female rats exposed to scream sound were presented with reduced weight gain and sucrose preference, while immobility time in forced swim test and serum corticosterone concentration were significantly increased. Scream sound stress sequentially decreased plasma anti-Müllerian hormone and estradiol concentration, induced primordial and preantral follicles loss, augmented granulosa cell apoptosis in ovarian growing follicles, and eventually decreased litter sizes. Based on these results, we suggest that chronic PS induced loss of ovarian reserve by accelerated primordial follicle activation and destruction of growing follicles, which results in follicle depletion and decreased fertility.