Contraceptive intervention by vas occlusion using copolymer styrene maleic anhydride sma in male rats and in vitro study in dogs

Abstract

The non-hormonal, copolymeric, contraceptive agent, Styrene maleic anhydride (SMA) is expected to provide a valuable addition to the current options of canine male contraception. The present study was conducted to determine the in vitro spermicidal action of copolymer SMA on canine ejaculatory spermatozoa and to study the in vivo vas occlusion contraceptive effect of copolymer SMA, followed by its reversal using dimethyl sulphoxide (DMSO) and sodium bicarbonate (NaHCO3) in male Wistar rats. newlineIn vivo vas occlusion reversal experiment was also carried out in twelve Wistar rats (G VI) using solvents viz., DMSO and 5 per cent NaHCO3. At 60 days of post-reversal period, fertility trials showed 67 and 83 per cent restoration of fertility in DMSO and NaHCO3 reversed group of rats, respectively. SEM studies showed that the vas lumen was occluded with white, amorphous substances which anchored newlineinto the vas mucosal wall by invagination and blocked the patency. Following vas occlusion reversal, vas lumen regained its patency with loss of SMA copolymer plug in the vas lumen and complete regeneration in the vas epithelium was seen. All other parameters viz. haematology, serum biochemistry and testosterone remained unaltered in vas occluded and reversal rats. Thus, use of copolymer SMA as vas occlusive agent was found to be safe, effective and could provide hope as a reversible male contraceptive in canine. newline