Tobacco smoke disrupts testicular microcirculation in the rat.

Anaesthetized adult rats were exposed repeatedly to cigarette smoke for 2 s interspersed with exposure to fresh air for either 10, 15 or 30 s using a smoking apparatus. The acute effects of this treatment on testicular microcirculation were studied using laser Doppler flowmetry. Peripheral tissue O2 saturation was measured continuously in the foot during the experiment. Exposure to cigarette smoke caused a moderate acute increase in the testicular blood flow and it inhibited vasomotion. Blood flow and the pattern of vasomotion were normalized after termination of smoke exposure. The time between the last smoke exposure and flow normalization was dependent on the smoke/air dose. Peripheral tissue O2 saturation did not change during the experiments. The effects on testicular microcirculation of local injections of an aqueous extract of cigarette smoke and passive smoking were also studied. Local injection of smoke extract increased blood flow and inhibited vasomotion. Passive smoking caused a moderate decrease in the frequency of vasomotion and amplitude. The observation that cigarette smoke influences testicular microcirculation acutely is discussed in relation to possible adverse effects on spermatogenesis.