Sub‐chronic restraint stress exposure in adult rats: An insight into possible inhibitory mechanism on testicular function in relation to germ cell dynamics

Abstract

Psychological stress is now widely recognized as one of the major risk factors for male fertility. Its impact on the dynamics of testicular germ cells, however, has yet to be fully investigated. Therefore, we used the rat restraint stress (RS) model as a psychological stressor to assess the impact of psychological stress on testicular germ cell dynamics. Adult male SD rats were exposed to sub-chronic RS for 1.5 and 3 h per day for 30 days. The quality of cauda epididymis spermatozoa was adversely affected by RS exposure, and the frequency of spermatozoa with tail abnormalities was higher than that of spermatozoa with head abnormalities. RS exposure adversely affected testicular daily sperm production by disturbing the meiotic and post meiotic germ cell kinetics in the testis. The histomorphology of the testis was altered by loosening and vacuolization in the seminiferous epithelium, germ cell exfoliation and the presence of giant cells. Seminiferous tubules of stage I-VI and VII-VIII were severely affected in rats exposed to RS for 3 h. By interfering with steroidogenic enzymes, RS exposure disrupts testosterone biosynthesis. The testicular oxidative balance was also disturbed by RS exposure, which disrupted the levels/activities of lipid peroxidation, Nrf-2, superoxide dismutase and catalase. There was also an increase in caspase-3 activity and a decrease in the Bax-Bcl2 ratio. In conclusion, our findings suggest that psychological stressors like RS impair testicular functions in rats by disrupting germ cell dynamics, downregulating testicular androgenesis and increasing oxidative stress and apoptosis.

Sub-Chronic Restraint Stress Suppresses Sexual Potency and Erection Efficiency by Targeting the Hypothalamic-Pituitary-Testicular Axis and the Nitric Oxide/Cyclic Guanosine Monophosphate/Phosphodiesterase 5α Pathway in Adult Rats

“…Psychological stress is medically recognized as a risk factor for male potency; however, it is difficult to investigate and assess the extent of its impact on penile erection as well as to determine its mechanism of action. We therefore used the rat RS model that has a comparable effect in humans to better understand the effects of psychological stress on male sexual potency and erection efficiency [27, 28].…”

“…The Institutional Animal Ethics Committee of Banaras Hindu University approved this experimental plan (approval number: BHU/DoZ/IAEC/2018-19/063). Sub-chronic exposure of RS for 30 days is based on our previous study and its findings [27]. Rats were randomly allocated into three groups (9 rats/ group) as follows:…”

“…The restraint stress (RS) rodent model is an experimental model for psychological stress which has comparable effects in humans [27, 28]. RS has a negative impact on testosterone biosynthesis and semen quality while increasing oxidative stress [29, 30].…”

“…RS has a negative impact on testosterone biosynthesis and semen quality while increasing oxidative stress [29, 30]. Recently, we reported that sub-chronic RS impairs rat testicular function by disrupting testicular germ cell dynamics, steroidogenesis, and oxidative balance, as well as increasing apoptosis [27].…”

“…RS has a negative impact on testosterone biosynthesis and semen quality while increasing oxidative stress [29,30]. Recently, we reported that sub-chronic RS impairs rat testicular function by disrupting testicular germ cell dynamics, steroidogenesis, and oxidative balance, as well as increasing apoptosis [27]. Therefore, by using the rat RS model, the objectives of this study were to comprehensively understand the harmful effects of psychological stress on sexual potency and erection efficiency.…”