Suppression of the sympathetic nerve activity after surgical reversal of two-kidney, one clip hypertension in rats.
The change in tonic renal efferent sympathetic nerve activity (RSNA) was studied during the rapid fall in mean arterial pressure (MAP) after surgical reversal of two-kidney, one clip hypertension in rats (RHR). Controls used were intact RHR exposed to the same fall in MAP induced by slow infusion of sodium nitroprusside. Within 2 h after declipping, MAP had fallen from 191 +/- 9 mmHg to 106 +/- 8 mmHg. During this decline in pressure, the reflex increase in RSNA, ordinarily following a decrease in pressure, was clearly suppressed; after a short and transient initial increase, RSNA was below the control level. In comparison, upon vascular dilatation with sodium-nitroprusside, the same fall in MAP was accompanied by a 117 +/- 30% increase in RSNA (P less than 0.01). Thus, the rapid normalization of MAP after reversal of renovascular hypertension involves a mechanism that exerts a suppressive action on the efferent sympathetic activity.
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D006978:Hypertension, Renovascular / Q000188:drug therapy / Q000503:physiopathology* / Q000601:surgery; D007668:Kidney / Q000294:innervation* / Q000503:physiopathology; D008297:Male; D009599:Nitroprusside / Q000627:therapeutic use; D051381:Rats; D011919:Rats, Inbred Strains; D013564:Sympathetic Nervous System / Q000503:physiopathology*; D013997:Time Factors; D014664:Vasodilation / Q000187:drug effects
D009599:Nitroprusside