Testicular cells exhibit similar molecular responses to cigarette smoke condensate ex vivo and in vivo

Male exposure to cigarette smoke is associated with seminal defects and with congenital anomalies and childhood cancers in offspring. In mice, paternal exposure to cigarette smoke condensate (CSC) causes molecular defects in germcells and phenotypic effects in their offspring. Hereweused an ex vivo testicular explantmodel and in vivo exposure to determine the concentration atwhichCSCimpairs spermatogenesis and offspring development. We explanted testis tissue at postnatal day (P) 5.5 and cultured it until P11.5. Assessment of growth parameters by analyzing expression of cell-specificmarkers revealed that the explant systemmaintained structural and functional integrity. We exposed the P5.5 to -11.5 explants to various concentrations (40-160 mu g/ml) of CSC and confirmed that nicotine intheCSCwasmetabolizedto cotinine. We assessedvarious growthanddifferentiationparameters, aswell as testosterone production, and observed thatmany spermatogenesis featureswere impaired at 160 mu g/ml CSC. The same parameters were impaired by a similar CSC concentration in vivo. Finally, females mated to males that were exposed to 160 mu g/mlCSCneonatally had increased rates of pup resorption. Weconclude thatmale exposure toCSC impairs offspring development and that the concentration atwhich CSC impairs spermatogenesis is similar in vivo andex vivo. Given that the concentrations of CSC we used contained similardoses ofnicotine as human smokers are exposed to, we argue that our modelmimics human male reproductive effects of smoking.