Effect of renal denervation on the development of hypertension in spontaneously hypertensive rats

The involvement of the renal nerves in the development of hypertension in Okamoto spontaneously hypertensive rats (SHR) was investigated by performing bilateral renal denervation in a group (n = 7) of SHR at 8 weeks of age. A sham-operated group (n = 7) of SHR served as surgical controls. Systolic arterial pressure was recorded twice a week until 14 weeks of age using a tail cuff method. Renal denervation significantly (P less than 0.01) altered the time course for development of hypertension, although both groups eventually developed hypertension. During the 6-week observation period, there were no significant differences in body weight, average 24-h food and fluid intake, urine output, or Na+ and K+ excretion between the two groups. At 20 weeks of age there were no significant differences in systolic pressure, average fluid intake, or urine output between the sham and denervated groups. These results suggest that the renal nerves may be involved in the early phase of development of hypertension in the SHR. The possibility that altered renal function may be the mechanism of the above effects is discussed.