Anti-Platelet Therapy with Clopidogrel Prevents Endothelial Dysfunction and Vascular Remodeling in Aortas from Hypertensive Rats

The aim was to investigate the beneficial effects of clopidogrel in thoracic aorta function and structure and to characterize if P2Y(12) receptors contribute to these effects. Male Sprague Dawley rats were infused with angiotensin II [(Ang II) 60 ng.min(−1), 14 days] or saline (control rats) and were simultaneously treated with clopidogrel (10 mg.kg(−1).day(−1)) or vehicle. After 14 days, systolic blood pressure (mmHg) was similar in Ang II-hypertensive rats treated with clopidogrel or vehicle (199±9 vs. 190±11, respectively). Systolic blood pressure in control rats was not altered by clopidogrel treatment (128±1 vs. vehicle, 134±2). Endothelium-dependent relaxation induced by 2-MeS-ADP was decreased in aortas from vehicle-treated Ang II-hypertensive rats, compared to vehicle-treated control rats. This response was elicited via activation of P2Y(1) and P2Y(12) receptors. In the presence of L-NAME and indomethacin, 2-MeS-ADP induced contraction and this response was augmented in vehicle-treated Ang II-hypertensive rats, compared to vehicle-treated control rats. The contraction to 2-MeS-ADP was evoked by P2Y(13) and P2Y(12) receptor activation. Clopidogrel-treatment did not normalize relaxation or contractile responses induced by 2-MeS-ADP in aortas from Ang II-hypertensive rats. P2Y(1) and P2Y(12) protein expression was increased, whereas P2Y(13) receptor expression was reduced in aorta from vehicle-treated Ang II-hypertensive rats. Endothelium-dependent relaxation upon acetylcholine-stimulation was reduced in vehicle-treated Ang II-hypertensive rats, and clopidogrel treatment was effective in improving endothelial function. Clopidogrel also prevented vascular remodeling, evidenced by augmented media thickness in aortas from Ang II-hypertensive rats. Clopidogrel has beneficial effects on the aortic endothelium of Ang II-hypertensive rats, but its effects do not seem to be directly related to the presence of P2Y(12) receptors in this vessel.