Mitochondrial membrane potential (MMP) regulates sperm motility

Abstract

Sperm motility is the major decisive factor in determining male fertility. The objective of the present study was to analyse the effect of mitochondrial membrane potential (MMP) on the temporal regulation of sperm motility. Observations were recorded in various rodent species and among differentially motile sperm fractions including swim up and leftover layer of human semen sample using JC-1 stain (a marker of the MMP) through FACS. Swim-up sperms having highest motility showed significantly higher MMP as compared to leftover sperms, which had the least motility. Interestingly, infertile patients with compromised motility showed low MMP as compared to the healthy individuals. Further, as per the time lapse, sperm motility goes down, at the same time, it was observed that MMP also decreases in human as well as in rodent sperms. Treatment of known spermicides on human sperms reduced their motility drastically which in turn also reduced its MMP significantly. Treatment of human sperms with oxidative uncoupler also impeded their motility by reducing MMP, indicating a definitive role on MMP on sperm motility and fertility. Based on the results of the study, MMP can be considered as a potential regulator and indicator of sperm motility and hence could be directly related to male fertility.

Keywords: Infertility; Mitochondrial membrane potential; Sperm motility; Spermatozoa.