Aldosterone increased by chronic unpredictable mild stress damages epididymal sperm quality in young rats

In young rats, aldosterone concentration increases in response to stress. Aldosterone can decrease testosterone production. We hypothesized that aldosterone impairs sperm quality, and that this impairment is reversible with 50 mg/kg of eplerenone in young rats. Forty-two young male Wistar rats (51 days old) were divided into six groups: Control, Control + vehicle (C + Veh), chronic unpredictable mild stress (CUMS), and CUMS + eplerenone at three concentrations: 25, 50, and 100 mg/kg bw, a selective aldosterone blocker (CUMS + EP) (n = 7 per each). On postnatal day 51, eplerenone was administered orally via gastric tube 2 h before the start of the stress test. The CUMS paradigm was administered once daily at various times, without repeating the stressor, over a four-week period. We evaluated the effects of chronic stress on serum testosterone concentrations, oxidative stress, apoptosis, and sperm quality. The CUMS group exhibited low testosterone levels and poor epididymal sperm quality. Compared to the CUMS group, the 50 mg/kg dose of eplerenone demonstrated significant improvements in sperm motility (28.8 %), sperm viability (36.9 %), and sperm concentration (58.9 %). In the CUMS context, the 100 mg/kg dose was toxic because it induced oxidative stress and apoptosis. Aldosterone negatively affects epididymal sperm quality by reducing testosterone-induced sperm motility, viability, and concentration. Aldosterone impairs sperm quality, which is reversible with 50 mg/kg of eplerenone. The prevention by eplerenone supports our hypothesis.