Comparative Observations on Ciliary Currents in Mammalian Oviducts

Abstract

Oviducts of 4 mammalian species (cow, sheep, guinea pig and rat) were slit open longitudinally, while submerged in Hanks'' balanced salt solution at 37.degree. C, in order to expose the lining mucosa. The direction of ciliary currents on the mucosa was assessed by applying particulate matter (15 .mu.m microspheres or stained Lycopodium spores) to the surface. In cow and sheep oviducts, the particles were transported toward the uterine end when applied to either the ampulla or the isthmus, in contrast to the pro-ovarian ciliary currents demonstrated earlier in the isthmus of pig and rabbit oviducts. No ciliary currents could be detected in the isthmus of guinea pig and rat oviducts. Scanning EM revealed the extreme scarcity of ciliated cells in the isthmus of the latter 2 species. The significance of ciliary activity for gamete transport in the isthmus of the oviduct apparently varies remarkably among species. Sperm transport was most likely achieved by a mechanism independent of ciliary action.