The effect of renal sympathectomy on blood pressure and plasma renin activity in spontaneously hypertensive and normotensive rats.

Renal denervation delays the development of hypertension in spontaneously hypertensive (SH) rats. The influence of bilateral surgical renal sympathectomy, verified by fluorescence microscopy, on blood pressure and plasma renin activity in SH and normotensive rats (170-180 g before the sympathectomy) was studied. Neither in SH nor in normotensive rats, did the preoperative systolic blood pressure in the renal-sympathectomized group differ from that in the sham-operated controls. After the sympathectomy, blood pressure in the SH rats increased in 4 weeks only insignificantly, from 160 +/- 3 to 172 +/- 6 mmHg, while that in the sham-operated SH rats rose from 163 +/- 5 to 191 +/- 5 mmHg. In normotensive rats, blood pressures in both the renal-sympathectomized and sham-operated groups remained at the pre-operative levels. Thirty days after the operations, plasma renin activity or plasma kininogen in the renal-sympathectomized group did not differ from that in the sham-operated one either in SH or in normotensive rats. The results suggest that the delay in hypertension development produced by renal sympathectomy in SH rats is not mediated by a reduction in renin secretion.