AJP - Regulatory, Integrative and Comparative Physiology, Vol 249, Issue 4 496-R501, Copyright © 1985 by American Physiological Society
Selective efferent chemical sympathectomy of rat kidneys
L. M. LeNoble, R. W. Lappe, M. J. Brody, H. A. Struyker Boudier and J. F. Smits
Surgical denervation of kidneys results in interruption of both afferent
and efferent renal nerves. We attempted selective efferent renal
denervation in rats by slow infusions of 6-hydroxydopamine (6-OHDA) into
the right renal artery. Integrity of efferent renal nerves was assessed by
chemical and physiological methods and by measuring responses of mean
arterial blood pressure (MAP) and heart rate (HR) to intrarenal (ir)
infusion of bradykinin in conscious rats. Results were compared with those
in surgically denervated and ir saline-infused rats. Surgical denervation
of left kidney reduced renal norepinephrine (NE) to 58 and 14% of control
levels at 1 and 7 days, respectively, after surgery. Increase in left renal
resistance during posterior hypothalamus (PH) stimulation was only 70 +/-
28% (n = 5) compared with 289 +/- 69% (n = 6) in control animals. Response
in opposite kidney was unchanged. Although 0.1 mg 6-OHDA ir caused
considerable reduction of NE levels in both kidneys, responses to PH
stimulation were unchanged. 6-OHDA (1 mg) reduced NE levels in infused and
control kidney and atria. Functional evidence for denervation was only
obtained in the kidney infused with 6-OHDA. Responses of MAP and HR to ir
bradykinin were unchanged 7 days after 1 mg 6-OHDA. The data suggest that
ir 6-OHDA results in functional efferent sympathectomy without affecting
afferent renal nerves.
