[Cortical and medullary circulation of the kidneys in pressor and depressor sinocarotid reflexes]

An experimental study in 12 anesthesized rabbits has demonstrated, by means of the hydrogen clearance test, that carotid sinus baroreceptors participate in the control of both the cortical (CF) and the medullary (MF) renal flow. The direction and magnitude of CF and MF changes in case of sinocarotid reflexes are determined by the relationships between extrarenal nervous effects, systemic blood pressure (BP) and self-regulative response of the cortex and the medulla. Arterial hypotension during depressor sinocarotid reflexes is accompanied by decreased CF and MF, while blood pressure stabilization increases CF and MF in these conditions. Arterial hypertension associated with pressor sinocarotid reflexes is accompanied by decreased CF, whereas MF changes may take different directions depending on the severity of hypertension. In a denervated kidney, sinocarotid reflexes cause CF and MF changes of the same direction as changes in BP, which are, however, less pronounced due to self-regulative intrarenal mechanisms being switched on. Simultaneous denervation of the kidney and BP stabilization can prevent completely CF and MF changes associated with sinocarotid reflexes.