Aim: 

Arterial endothelium is a mechanic and biologic "barrier" and also an "organ" which secrets active factors necessary for vasomotoricity and integrity of vascular wall. One of the most important of these factors is nitric oxide which is released from endothelial cell at the action of acethylcholine or adenosine on specific receptors.

Methods: 

Our study performed, using an isolated organ bath, analysed the vascular reactivity of 20 guinea pigs thoracic aorta. We analyzed the dosage-effect curves to phenylephrine-PHE, adenosine-5'ADP and sodium nitroprusside-NPS, before and after an incubation with hydrosoluble cigarette extract smoke 5% during 1 hour. The statistics completed with Student t test and ANOVA test, show that exposure of guinea pigs to cigarette extract smoke determined a significant increase of the contractile response at PHE 10^-5 mol/l (p < 0.05) and a significant reduction of the endothelial-dependent relaxing response at 5'ADP 10^-5 mol/ l (p < 0.005), but does not significantly modify the endothelial-independent relaxing response to NPS 10^-5 mol/l (p = 0.05).

Conclusions: 

In conclusion, incubation with cigarette extract smoke of vascular rings has diminished the production of NO on action of ADP (endothelial-dependent relaxation), without the modification of the muscular response on action of NO from NPS (endothelial-independent relaxation).