Baroreflex sensitivity changes during the reversal of Goldblatt two-kidney one-clip hypertension in rats

The time-course of changes in baroreceptor reflex sensitivity during the reversal of Goldblatt two-kidney one-clip hypertension was studied in male Wistar rats. Groups of animals were studied before and 1, 3, 7, 14 and 25 days after removal of a left renal artery clip of 0.18 mm internal diameter. Normotensive rats of comparable ages were included as controls. Baroreflex sensitivity increased from 0.299 +/- 0.072 ms/mmHg (n = 8) in 25 day hypertensive rats to 0.657 +/- 0.155 and 0.786 +/- 0.093 ms/mmHg (n = 8) in 1 day and 3 day declipped animals respectively. Baroreflex sensitivity in the 1 day declipped rats was inversely related to the level of blood pressure. Baroreflex sensitivity is restored early when renovascular hypertension is reversed. This is unlikely to be due solely to regression of structural vascular adaptation.