Sperm Transport and Distribution in the Reproductive Tract of the Female Rabbit After Intraperitoneal Insemination

Abstract

Both live and dead spermatozoa were used to study the transport and distribution of sperm in the reporductive tract of 3 groups of rabbits. The female rabbits studied were: 1) rabbits in estrus and not treated, 2) rabbits injected with 25 IU of human chorionic gonadotrophin (HCG) 12 hours before intraperitoneal insemination, and 3) rabbits injected with HCG 96 hours before insemination. Upon autopsy, it was found that spermatozoa were transported in an abovarian and adovarian direction in the oviduct. Motile spermatozoa were more consistently recovered from the reproductive tract than immotile. Fewer spermatozoa were recovered from the reproductive tracts of pseudopregnant rabbits than rabbits in estrus or at ovulation. Sperm motility and oviduct contraction affect the pickup of spermatozoa by the fimbriae. Since most of the spermatozoa recovered from the oviduct were found in the ampulla, it is suggested that their abundance over those found in the isthmus was due to anatomical barriers in the oviduct created by the isthmus. Oviductal contractility is also seen to affect the distribution of sperm in the oviduct.