The purpose of this study was to determine if inhalation of mainstream (MS) or sidestream (SS) smoke affects the reproductive organs of female hamsters. Females inhaled smoke from one or two cigarettes twice per day for 30 d prior to mating using a smoking machine equipped for nose breathing. Serum cotinine levels were within the ranges found in active and passive humans smokers. On day 7 of pregnancy, the reproductive organs of controls and smokers were evaluated for the total number of corpora lutea (CL), the percentage of normal, pink, and small CL, the vascular area in the CL, the ultrastructure of the oviductal epithelium, the ratio of ciliated to secretory cells in the ampulla of the oviduct, the stretchability of the uterine horns, the percentage of implantation sites, and the percentage of touching implantation sites. All parameters, except the percentages of implantation sites and of small CL, were affected by exposure to smoke. To determine if the effects of smoking on the ovary and uterus could be reversed, females smoked for 30 d, remained in their cages without smoking for 30 d, and then were mated and evaluated on day 7 of pregnancy. In this reversal experiment, all ovarian and uterine parameters (except total CL) previously affected by smoking were normal in MS and SS females. These experimental observations show that components in both MS and SS smoke, when delivered at levels comparable to those human smokers receive, can affect the ovary, oviduct, and uterus.

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PubMedDate not supplied

Pyridines in cigarette smoke inhibit hamster oviductal functioning in picomolar doses.

Past studies showed that chemicals in cigarette smoke inhibit oviductal functioning in vivo and in vitro. The purposes of this study were to identify individual toxicants in cigarette smoke solutions that inhibit various aspects of oviductal functioning and to determine their effective doses using in vitro bioassays. Solid phase extraction and gas chromatography-mass spectrometry (GC-MS) were used to identify individual chemicals in mainstream (MS) and sidestream (SS) cigarette smoke solutions. Pyridines, which were the most abundant class of compounds identified, were purchased, assayed for purity, and tested in dose-response studies on hamster oviducts. The lowest observable adverse effect level was determined for each pyridine derivative using the oocyte pick-up rate, ciliary beat frequency, and infundibular muscle contraction assays. 2-Methylpyridine, 4-methylpyridine, 2-ethylpyridine, 3-ethylpyridine, and 4-vinylpyridine were inhibitory at picomolar concentrations in all assays. This work shows picomolar doses of pyridines with single methyl or ethyl substitutions significantly inhibit oviductal functioning raising questions regarding the safety of these compounds.

Animals↗

PubMedDate not supplied

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.

Animals↗