Abstract:
Dilantin, whose chemical name is diphenylhydantoin (DPH), is an anti-epileptic drug (AED) that has been shown to cause fertility issues in both women and men. Men experience infertility while taking AEDs due to sperm morphological and motility changes. CatSper is a calcium channel complex required for successful fertilization that is localized in sperm. Studies have shown that the CatSper calcium channel complex is needed for sperm to undergo hyperactivation during capacitation by comparing wild-type and CatSper-/- sperm in mice. Infertility occurs when the CatSper channel complex is disrupted and the sperm are unable to migrate towards and penetrate the egg inside the female reproductive tract. The goal of the proposed experiments was to determine if CatSper activity is altered by DPH treatment in vitro and to determine if treatment of male NSA mice with DPH altered the RNA and protein levels of CatSper in sperm using RT-PCR and immunofluorescence. Results of the sperm motility assay showed a slight (6-8%) but not significant decrease in sperm progressive motility between DPH-treated and NaOH vehicle control treated mice. Results from RT-PCR and immunofluorescence showed no significant reduction in CatSper expression. CatSper1, CatSperβ, and CatSperγ expression in RNA isolated from the testis did not differ in DPH and NaOH treated mouse sperm but none of these 3 CatSper RNAs were expressed in sperm from the cauda epididymis. There was a slight reduction (13%) in CatSper1 calcium channel abundance in sperm from DPH-treated mice compared to NaOH vehicle control treated mice but this difference was again not significant. These trends suggest that DPH induced changes in motility in vivo could be due to a DPH metabolite altering CatSper or other related voltage-gated ion channel activities in the sperm tail preventing hyperactivation and progressive motility and could be a cumulative effect of a number of small DPH induced changes.
