We determined the effect of pharmacological blood of the pericoronary nerve either along the experimentally occluded left circumflex (CX) or the nonoccluded left anterior descending coronary artery (LAD) on the reflex inhibition of renal nerve activity (RNA) during a brief CX occlusion. In 15 pentobarbital-anesthetized dogs with carotid sinuses denervated, CX was occluded under four different conditions of the pericoronary nerves. With intact pericoronary nerves, CX occlusion resulted in a significant decrease [-44 +/- 6.4 (SE) %] in RNA. The decrease in RNA remained basically the same (-34 +/- 10.0%) after block of the pericoronary nerve along LAD with local infiltration of 2% lidocaine. However, the reduction of RNA was abolished after block of the pericoronary nerve along CX (-6 +/- 4.9%) and after block of the pericoronary nerves along both LAD and CX (3 +/- 2.6%). These results indicate that the afferent input transmitted via the pericoronary nerve along the experimentally occluded coronary artery plays a dominant role in mediating the reflex inhibition of RNA during the coronary occlusion.
