Carotid Sinus Participation in Experimental Renal Hypertension

Using direct electroneurographic technics, it is shown that the carotid sinus baroceptor reflexes adapt or reset to the higher pressure levels of chronic renal hypertension. They remain functional at the higher pressure level and thus act to maintain rather than to oppose it. This provides a satisfactory explanation for the presence of significant neurogenic vasoconstriction in chronic hypertension. Experiments on acutely hypertensive dogs indicate that the resetting process starts quite early but seems to lag behind the rise in arterial pressure.