The Effect of Prenatal Exposure to Nicotine on Pituitary –Testicular Axis and Diminishing Steroidogenic Acute Regulatory Protein Expression in Albino Rats

-Cigarette smoking prevalence is still increasing in the developing world especially among men mainly in central Asia, east Europe and Africa. Furthermore, maternal cigarette smoking during pregnancy has multiple deleterious effects on the offspring, which may persist into adulthood. The present study was done to evaluate the pituitary-testicular activities of rats subjected to chronic nicotine treatment. The testicular key androgenic enzymes activities, plasma and intratesticular testosterone (ITT) concentrations, and plasma concentration of gonadotropin were significantly reduced by nicotine treatment along with the decreased sperm counts and the disruption of spermatogenesis indicated by significant reduction in the number of different generations of germ cells at stage VII of the spermatogenesis cycle with increased sperm head abnormalities. The Western blot and the reverse transcriptase-PCR analysis revealed that the nicotine induced a marked decrease in the expression of testicular steroidogenic acute regulatory (StAR) protein, which helps in the transfer of cholesterol in mitochondria for the testosterone biosynthesis. Human chorionic gonadotropin or taurine supplementation with nicotine prevented the degeneration of germ cells to some extent, restored spermatogenesis moderately with decreased sperm head abnormalities, and enhanced sperm counts, accompanied with increase in plasma and ITT concentrations, testicular StAR gene expression, and key androgenic enzymes activities. The results indicated that nicotine caused testicular toxicity by germ cell degeneration, inhibition of StAR gene expression along with androgen production in adult male rats probably by affecting pituitary gonadotropin,