Cortisol modulates Ca2+ signaling and acrosome reaction in human sperm

Stress and elevated cortisol levels have negative effects on fertility, although there is controversy about the effect of cortisol on human sperm. One study reported that hydrocortisone (HC), the synthetic form of cortisol, does not activate CatSper channel but is able to inhibit its activation by progesterone (Pg). However, subsequent reports showed that HC has an agonist effect on CatSper, producing intracellular Ca2+ ([Ca2+]i) increases. These studies were performed using only electrophysiological techniques and fluorometric measurements of Ca2+. Therefore, it is important to evaluate the effects of different HC concentrations on human sperm physiology using other approaches and techniques.