Aim: Clopidogrel is an antiplatelet agent that inhibits platelet aggregation. It is frequently used in cases of impaired vascular blood flow such as coronary artery disease and as maintenance after treatment. The fact that it is used so frequently suggests that its effects on other systems besides its effects on the cardiovascular system are worthy of investigation. In addition, clopidogrel has been shown to have inhibitory activity on bladder smooth muscle in a previous study conducted by us. Therefore we aimed to investigate the possible effects of clopidogrel on bronchus.

Methods: Adult female Sprague-Dawley rats (n=9) were used.The rats were decapitated in diestrus and their main bronchi were isolated. 3 mm ring-shaped strips were obtained from the bronchi. Bronchi were suspended in isolated organ baths. After the completion of the regulation process, 0.1 µM and 10 µM doses of clopidogrel were administered non-cumulatively and the same procedure was repeated on 10 µM acetylcholine (Ach)-induced bronchi. The effects of clopidogrel were evaluated in terms of maximal contraction amplitude (Emax) and isometric contractility indices. The data obtained were normalized as percentages and analyzed using paired t-test.

Results: 0.1 µM and 10 µM clopidogrel administration did not cause a statistically significant difference in Emax value. In Ach-induced bronchial smooth muscle, 0.1 µM clopidogrel administration did not cause a statistically significant change, while 10 µM dose caused a statistically significant decrease in Emax values (P<0.05).

Conclusions: Clopidogrel administration had an inhibitory effect on Ach-induced contraction of bronchus. This effect should be considered in the clinical use of clopidogrel.