DE: Role of cardiac, pulmonary, and carotid mechanoreceptors in the control of hind-limb and renal circulation in dogs. Circ Res 37

Reflex control of hind-limb and renal resistance vessels by cardiac and pulmonary receptors was studied by interrupting afferent vagal nerve traffic when only the heart or only the lungs were in situ in anesthetized dogs with sinoaortic denervation. During normocapnia, interruption of cardiac and of pulmonary vagal traffic decreased hind-limb blood flow (constant-pressure perfusion) by 23 % and 21%, respectively. Corresponding decreases in renal blood flow were 23 % and 33%. Hypercapnia augmented the decreases in renal blood flow due to the vagal block. Thus, the inhibitions exerted by the heart and lung receptors on these two beds were similar during normocapnia but were greater on the renal vessels during hypercapnia. In closed-chest dogs with their aortic nerves sectioned and their carotid sinus pressure controlled, combined withdrawal of carotid and cardiopulmonary inhibition decreased hind-limb and renal blood flow by about 80 % and 40%, respectively, during both normovolemia and hypervolemia. Interruption of cardio-pulmonary inhibition was responsible for 17 % and 31 % of the decrease in hind-limb blood flow at normal and increased blood volumes, respectively; values for the decreases in rena