Nicotine-induced damages in testicular tissue of rats; evidences for bcl-۲, p۵۳ and caspase-۳ expression

Objective(s): Present study was performed in order to uncover new aspects for nicotine-induced damages on spermatogenesis cell lineage. Materials and Methods: For this purpose, ۳۶ mature male Wistar rats were divided into three groups as; control-sham (۰.۲ ml, saline normal, IP), low dose (۰.۲ mg/kg BW-۱, IP) nicotine-received and high dose (۰.۴ mg/kg BW-۱, IP) nicotine-received groups. Following ۷ weeks, the expression of bcl-۲, p۵۳ and caspase-۳ at mRNA and protein levels were investigated by using reverse-transcriptase PCR (RT-PCR) and immunohistochemical (IHC) analyses, respectively. Moreover, the serum level of FSH, LH and testosterone were evaluated. Finally, the mRNA damage was analyzed by using special fluorescent staining. Results: Nicotine, at both dose levels, decreased tubular differentiation, spermiogenesis and repopulation indices and enhanced cellular depletion. Animals in nicotine-received groups exhibited a significant (P<۰.۰۵) reduction at mRNA and protein levels of bcl-۲. More analyses revealed a remarkable (P<۰.۰۵) enhancement in expression of p۵۳ and caspase-۳ in comparison to control-sham animals. Finally, nicotine resulted in a significant (P<۰.۰۵) reduction in serum level of testosterone and elevated mRNA damage. Conclusion: Our data showed that, nicotine by suppressing the testosterone biosynthesis, reducing mRNA and protein levels of bcl-۲ and up regulating the p۵۳ and caspase-۳ mRNA and protein levels adversely affects the spermatogenesis and results in cellular depletion.

Keywords:

Apoptosis , Bcl-۲ , Caspase-۳ , Nicotine , P۵۳ , Testis , Testosterone