Importance of the sympathetic nervous system in the development of renal hypertension in the rat

Abstract

Summary1. Chemical sympathectomy with 6-hydroxydopamine (6-OHDA) prevented the development of renal hypertension in 80% of weanling male rats of the C.F. strain. 2. Adult male rats treated with 6-OHDA developed hypertension on bilateral clamping of the renal arteries. 3. Demedullation of the adrenal glands followed by 6-OHDA treatment in adult rats prevented the development of hypertension in 75% of them. 4. Weanling rats treated with 6-OHDA did not have any measurable catecholamines in their hearts up to 72-78 days after treatment. 5. Unlike the weanling rats, the hearts of adult rats (demedullated or with intact medulla) showed significant refilling (40-50%) of catecholamine stores 60 days after 6-OHDA treatment. 6. It is concluded that the functional sympathetic nervous system is important in the development of renal hypertension in the rat.

Pre- and postjunctional inhibition of vascular sympathetic function by captopril in SHR. Implication of vascular angiotensin II in hypertension and antihypertensive actions of captopril.

“…There is now little doubt that the sympathetic nervous system plays an important contributory role in the maintenance of twokidney RHR, a role that grows more important as the duration of hypertension increases. 21 " 23 Similarly, the sympathetic nervous system is important in the development as well as the maintenance of hypertension in SHR. Thus, drugs that interfere with sympathetic function are effective in reducing both chronic renal and spontaneous hypertension.…”

Renal Haemodynamics in Conscious Experimentally Hypertensive Rats

“…Normal plasma catecholamine levels found in two-kidney, one-clip hypertensive rats do not exclude the possibility of adrenergic participation in regulating renovascular resistances. Both increased (Grewal & Kaul, 1971) and decreased (Dargie, Franklin & Reid, 1977) sympathetic tone in this form of hypertension have been reported.…”

“…Unfortunately the conditions of the present experiments eliminated the possibility of calculating renal haemodynamics in these kidneys. Speculatively, potential increase in renovascular resistances could be attributed to activation of the renin-angiotensin (Gavras, Brunner, Vaughan & Laragh, 1973) and sympathetic system (Grewal & Kaul, 1971).…”

Sympathetic and renin-angiotensin system influence on blood pressure and renal blood flow of two-kidney, one clip Goldblatt hypertensive dog.

“…When 6-hydroxydopamine was given intracisternally in doses of 250 jig two to three times before clamping, it prevented 1K-1C Goldblatt hypertension from developing, 10 but had no effect on 2K-1C hypertension. 17 When administered systemically, 6-hydroxydopamine combined with adrenal medullectomy inhibited the development of 2K-1C hypertension in adult and weanling rats, 18 but only delayed the full complement of 1K-1C hypertension. 19 Large-dose guanethidine treatment of newborn rats, not combined with adrenalectomy, failed to alter the development of 1K-1C or 2K-1C hypertension."…”

“…Based on the ability of 6-hydroxydopamine given intracisternally to prevent induction of 1K-1C, but not 2K-1C, Goldblatt hypertension, and the finding of an increased plasma catecholamine level in the former but not latter model, it was concluded that neither the central nor peripheral sympathetic nervous system participates in 2K-1C Goldblatt hypertension in the rat. 17 ' » Because of previous suggestions in the literature for sympathetic involvement in 2K-1C Goldblatt hypertension, 18 ' 23 and the known interactions of angiotensin with both central 24 and peripheral components of the sympathetic nervous system, 25 we initiated this investigation. We wished to determine the influence of the sympathetic and renin-angiotensin systems on the blood pressure and renal blood flow in the 2K-1C Goldblatt hypertensive dog.…”