SPERM ASCENT THROUGH THE OVIDUCT OF THE HAMSTER AND RABBIT IN RELATION TO THE TIME OF OVULATION

Abstract

Summary. Female golden hamsters were mated either about 5 to 8 hr before ovulation or about 2 hr after ovulation. At various intervals after mating, a ligature was placed slightly above the intramural portion of the oviduct, thus preventing further sperm ascent. In the females mated before ovulation, the percentages of eggs fertilized, as examined 10 to 12 hr after the estimated time of ovulation, were 16·8, 39·6, 58·3 and 81·4 when oviducts were ligated 1, 2, 4 and 6 hr after mating, respectively. In the females mated after ovulation, on the other hand, 37·5 and 92·0% of eggs were fertilized following ligation of oviduct at 0·5 and 1 hr after mating, respectively. Examination of complete serial sections of oviducts fixed 1 hr after mating showed that the oviducts of females mated after ovulation contained a relatively larger number of spermatozoa in their upper reaches than those of females mated before ovulation. It is concluded that in the hamster the ascent of spermatozoa through the oviduct takes place more rapidly when females are mated after ovulation than before ovulation. When rabbits were mated 8 and 4 hr before or 2 hr after ovulation, and their utero-tubal junctions were ligated 2 hr later, the fast sperm ascent after ovulation was not demonstrated.