AMP-activated protein kinase activator AICAR acutely lowers blood pressure and relaxes isolated resistance arteries of hypertensive rats

OBJECTIVES:AMP-activated protein kinase (AMPK) activity may alter blood pressure by directly influencing vascular tone. The purpose of this study is to examine if these effects occur acutely in a model of hypertension. METHODS AND RESULTS:Using distinct groups of Wistar–Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) we compare baseline aortic and mesenteric artery AMPK activation (by immunoblotting), hemodynamic (blood pressure and heart rate via carotid catheter) and biochemical responses to an acute injection of AMPK activator 5-aminoimidazole-4-carboxyamide-1-β-D-ribofuranoside (AICAR) in vivo and vasomotor responses of isolated mesenteric vessels to AICAR exposure in vitro using myography. Mean arterial pressure (MAP) decreased from 196 ± 3 to 122 ± 15 mmHg (P