Chronic in vivo or acute in vitro resveratrol attenuates endothelium-dependent cyclooxygenase-mediated contractile signaling in hypertensive rat carotid artery

Abstract

Exaggerated cyclooxygenase (COX) and thromboxane-prostanoid (TP) receptor-mediated endothelium-dependent contraction can contribute to endothelial dysfunction. This study examined the effect of resveratrol (RSV) on endothelium-dependent contraction and cell signaling in the common carotid artery (CCA) from spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY). Acetylcholine (Ach)-stimulated endothelium-dependent nitric oxide synthase (NOS)-mediated relaxation in precontracted SHR CCA was impaired (maximum 73±6% vs. 87±5% in WKY) (P<0.05) by competitive COX-mediated contraction. Chronic (28-day) treatment in vivo (drinking water) with a ∼0.075 mgkg-1day-1 RSV dose affected neither endotheliumdependent relaxation nor endothelium-dependent contraction and associated prostaglandin (PG) production evaluated in non-precontracted NOS-blocked CCA. In contrast, a chronic ∼7.5 mgkg-1day-1 RSV dose improved endothelium-dependent relaxation (94±6%) and attenuated endothelium-dependent contraction (58±4% vs. 73±5% in No-RSV) and PG production (183±43 vs. 519±93 pg/ml) in SHR CCA, while U46619-stimulated TP receptormediated contraction was unaffected. In separate acute in vitro experiments, 20-μM RSV preincubation attenuated endothelium-dependent contraction (6±4% vs. 62±2% in No Drug) and PG production (121±15 vs. 491±93 pg/ml) and attenuated U46619-stimulated contraction (134±5% vs. 171±4%) in non-precontracted NOSblocked SHR CCA. Compound C, a known AMP-Activated protein kinase (AMPK) inhibitor, did not prevent the RSV attenuating effect on Ach-and U46619-stimulated contraction but did prevent the RSV attenuating effect on PG production (414±58 pg/ml). These data demonstrate that RSV can attenuate endothelium-dependent contraction both by suppressing arterial wall PG production, which may be partially mediated by AMPK, and by TP receptor hyporesponsiveness, which does not appear to be mediated by AMPK. endothelium-dependent