In summary, our results show that at least five chemicals present in cigarette smoke solutions inhibit CBF in vitro; however, only cyanide was present in sufficiently high concentrations in smoke solutions to account for this inhibition. Cyanide solutions also inhibit OPR in a dose-dependent manner. Since inhibition of CBF by cyanide was completely reversible, it is unlikely that the effect is due to inhibition of cytochrome oxidase. Moreover, oviductal cilia were extremely sensitive to KCN, and inhibition of CBF and OPR occurred at cyanide concentrations much lower than those usually used to deplete ATP. However, our observations are consistent with the idea that cyanide produces a rapidly reversible effect at the level of the plasma membrane; this effect decreased CBF, which in turn led to a decrease in OPR. birth control pills
The precise effect of cyanide on ciliated cells of the oviduct is not known but could involve a decrease in cytosolic pH, which would decrease hydrolysis of ATP by dynein and thereby slow CBF. Since OPR is about 3 times more sensitive to cyanide than CBF, it is probable that cyanide affects other ciliary parameters such as metachrony and amplitude. These findings suggest a mechanism that could interfere with pick-up of the OCC in smokers, thereby leading to the increased incidence of ectopic pregnancy and infertility often seen in smokers. This paper identifies cyanide as a component of cigarette smoke that decreases CBF and OPR of mammalian oviducts. However, smoke solutions must contain additional components that alter OPR, as the inhibition of OPR observed in both MS and SS smoke solutions is not reversible.