A Comparative Study of the Contraceptive Mechanism of the Cu-Intrauterine Device and the Plastic-Intrauterine Device in Rats

KATSUYUKI TAKAHASHI, YOKO HIROSE, ATSUSHI HANEDA, TADASHI MIZUKAMI, KUNIHIRO OKAMURA, MASAKUNI SUZUKI
1978 Tohoku journal of experimental medicine  
Comparative Study of the Contraceptive Mechanism of the Cu-Intra uterine Device and the Plastic-Intrauterine Device in Rats. Tohoku J. exp. Med., 1978, 126 (4) 325-333 -After inserting the Cu-IUD and plastic-IUD into the horn of the uterus of rats, vaginal smears were daily observed for twelve estrus cycles, but no abnormal changes were noted. The female rats with the IUD were exposed to impregnation placing together with male rats. Neither the Cu-IUD nor the plastic-IUD affected copulation,
more » ... cted copulation, and a complete contraceptive result was obtained in these rats. There were no significant differences in any effect examined between Cu-IUD and plastic-IUD groups. In order to investigate the influence of copper on the penetration of sperm, we placed the rats with the IUD under direct observation and then exposed them to natural copulation. By examining various sites of the reproductive organs 30 min after copulation, the hindrance of sperm migration by the Cu-IUD was confirmed. IUD; experimental study of contraception; rat With worldwide expansion of population becoming an everincreasing social problem, researches concerning contraception are of great significance, and various contraceptive methods are being investigated on all quarters. Among these are oral contraceptive (pill) and intrauterine devices (IUD), methods which are valued for their superior results and which represent the most widely disseminated birthcontrol techniques to date. With regard to the IUD, besides the heretofore utilized inert IUD, the active IUD has been developed and reported as manifesting a higher level of contraceptive effect. However, as for the mechanism through which the active IUD functions, there are numerous aspects which remain as yet unclear. The purpose of the present paper is to elucidate the mechanism of the contraceptive action of the Cu-IUD in rats. The experiments were performed with respect to its influence on the estrus cycle and on sperm deposited in the female reproductive tract. On all points a comparative study utilizing the plastic-IUD vis-a-vis the Cu-IUD was concurrently conducted. Received for publication, February 8, 1978. 325
doi:10.1620/tjem.126.325 fatcat:ulgmxxneqzdh3o55dad2xnam4i