Cigarette smoke inhibits oocyte cumulus complex pick-up by the oviduct in vitro independent of ciliary beat frequency.

The purpose of this study was to quantify the effects of acute exposure to mainstream (MS) and sidestream (SS) smoke solutions on oocyte cumulus complex pick-up rate in explants of hamster oviducts using a newly developed in vitro assay. Experiments were performed in handmade perfusion chambers using infundibula from hamster oviducts and oocyte cumulus complexes harvested from mature ovarian follicles. Oocyte cumulus complex pick-up rate was measured by placing a stained oocyte cumulus complex at the base of the infundibulum and recording the length of time needed for the complex to traverse a defined path to the ostium. Addition of either whole MS or SS smoke solutions to the perfusion chamber caused a dose dependent decrease in oocyte cumulus complex pick-up rate. Unexpectedly, upon washout of smoke solutions with control medium, oocyte cumulus complex pick-up rate continued to decline. The gas phase of MS smoke is more inhibitory than the particulate phase, while SS gas and particulate phases inhibit oocyte cumulus complex pick-up rate at equivalent doses. Ciliary beat frequency and oocyte cumulus complex pick-up rate were measured using the same infundibular explants to determine if smoke solutions decrease oocyte cumulus complex pick-up rate by inhibiting ciliary beat frequency. Ciliary beat frequency decreased in MS smoke solutions and recovered either partially or completely after washout of the smoke solutions. SS smoke solutions either produced no change in ciliary beat frequency or stimulated ciliary beat frequency. Oocyte cumulus complex pick-up rate decreased in both MS and SS smoke solutions and further declined during washout when ciliary beat frequency was equivalent to or higher than controls. These data show that oocyte cumulus complex pick-up rate and ciliary beat frequency can be uncoupled and that smoke solutions inhibit oocyte cumulus complex pick-up rate by affecting factors in addition to ciliary beat frequency. Possible reasons for the smoke induced decrease in oocyte cumulus complex pick-up rate are discussed. These results may explain the increased incidence of tubal infertility and ectopic pregnancy observed in women who smoke.