Aim: 

Chronic exposure to cigarette smoke induces endothelial dysfunction by decreasing the endothelial-dependent vasodilator response to acetylcholine, without changing the endothelial-independent vasodilator response to sodium nitroprusside. The purpose of the study was to test if the physical exercise improves the endothelial dysfunction induced by chronic exposure to cigarette smoke.

Methods: 

A number of 16 guinea pigs were exposed for 10 weeks to cigarette smoke (5 cigarettes/day, 3 cigarettes/ hour, 20 minutes interval, twice a day). From these 16 guinea pigs, 8 were trained on an ergonomic device (a moving carpet), increasing the time (60 – 90 min.) and the intensity of the physical effort (0°– 20° slope), with the speed of 0.25 m/s, for 10 weeks. The results were compared with the control group (n = 8). In the isolated organ bath, the vascular preparations' reactivity was evaluated by determining the dose – effect curves to acetylcholine (10^-9– 10^-4M) and sodium nitroprusside (10^-9– 10^-4M), obtained after the precontraction with phenylephrine 10^-5M.

Results: 

The dose-effect curves were compared based on all of the three parameters from Hill's sigmoidal equation: the maximal relaxation (%), EC50% (-log [M]) and the Hill coefficient. These curves showed a significant difference p < 0,001 between the groups regarding the vasodilator response to acetylcholine.

Conclusion: 

The physical exercise decreased the effects of chronic exposure to cigarette smoke on the endothelial-dependent vasodilatation and did not change the vascular smooth muscle responsivity.