OBJECTIVETo study the effect of cigarette smoke on the sexual function of male rats.

METHODSBased on Ozyurt's smoking model, we equally divided 30 male adult Sprague-Dawley rats into a control and a smoking group, and exposed the latter to cigarette smoke for 60 days. A week before the end of the experiment, we added 5 female rats to each group and observed their mating through 24-hour video surveillance. Sixty days later, all the rats were killed for the determination of the level of testosterone (T) in the plasma and the activity of nitric oxide synthase (NOS) in the corpus cavernosum, and Masson-dyeing image analysis of the penile tissue.

RESULTSCompared with the controls, the rats in the smoking group showed a significant reduction in the times of mating, the level of plasma T (P < 0.05) and the activity of NOS in the penile cavernous tissue (P < 0.05), but a slight increase in the collagen fibers and obvious changes in the blood sinuses.

CONCLUSIONCigarette smoke seriously affected penile erection in the experimental rats. The decrease in plasma T, NOS activity and the area of smooth muscle may be an important mechanism underlying their erectile dysfunction.