Effect of compounds structurally related to taurine and of taurine uptake inhibitors on the motility of hamster sperm in vitro

Several taurine‐related compounds, taurine antagonists and taurine uptake inhibitors were tested for their effect on hamster sperm motility in vitro. Hypotaurine was approximately three times more effective than taurine. N‐methyltaurine and taurocyamine were less effective. Inactive taurine‐related compounds were not effective blockers of taurine's spermtimulating activity. However, 1‐(4‐nitrophenyl)‐2‐dimethylaminomethyl‐l‐propenone, a taurine uptake inhibitor, completely suppressed sperm motility at a molar concentration equal to, or less than, that of the taurine added to the incubation medium and also suppressed the motility‐sustaining action of the cumulus oophorus.