Inner Calcium Stores and P2 Receptors are Involved in Regulating Reactivated Sperm Motility

Abstract

We used a sperm reactivation model to study the possible role of the sperm calcium inner stores in regulating sperm motility reactivation. Our results show that the release of calcium from the stores could be important for sperm motility reactivation. In addition, stimulating the release of calcium from the stores using drugs like thimerosal resulted in a significant change in motility pattern of reactivated sperm. Moreover, our immunofluorescence results showed—for the first time—the expression and localization of the two P2Y receptors, P2Y1 and P2Y2, and the P2X7 receptor on the sperm tail of mouse sperm. Inhibiting P2 receptors resulted in inhibition of sperm motility reactivation suggesting the possible role of the receptors in motility reactivation. In conclusion, the possible importance of the calcium inner stores and the P2 receptors in motility reactivation suggests that they might have a role in regulating sperm functions.