The contribution of adenosine receptor subtypes to vascular tone in mouse pudendal artery

Activation of adenosine receptors (ARs) has been implicated in a number of biological functions including cardiovascular, renal and erectile function. Recent studies suggested that only A2B AR may play an important role in penile tissue to regulate erectile function. However, no studies have been conducted on the vasculature supplying and controlling blood flow to the penis. Our aim was to determine the contribution of ARs in the regulation of vascular tone in pudendal artery (PA), the major artery supplying blood flow to the penis. Concentration response curves to non-selective AR agonist NECA were performed in PA isolated from WT, A2A and A2B AR KOs. Our data suggested that neither A1 nor A3 AR play an important role in PA vascular tone, while genetic deletion or pharmacological inhibition of both A2A and A2B ARs significantly decreased the NECA-mediated relaxation. Treatment of A2AKO or A2BKO PA rings with either A2B or A2AAR antagonists respectively abolished NECA-mediated relaxation. Pre-incubation of PA rings with L-NAME resulted in a significant decrease in NECA-mediated relaxation. Together, our data suggest that AR-mediated vasorelaxation is mediated by both A2A and A2BAR in PA and is partially dependent upon nitric oxide. (Supported by HL 094447, HL027339 and HL-071802).