AJP - Regulatory, Integrative and Comparative Physiology, Vol 249, Issue 5 634-R637, Copyright © 1985 by American Physiological Society
Selective destruction of renal afferent versus efferent nerves in rats
R. W. Lappe, R. L. Webb and M. J. Brody
Previous anatomic studies demonstrated that afferent projections from the
left kidney of the rat passed predominantly through the dorsal roots of
spinal segments T10-L1. Selective destruction of renal afferent nerves,
without damaging renal efferent nerves, was attempted by severing the
dorsal roots carrying the afferent fibers. In anesthetized rats, the dorsal
left side of the spinal cord was exposed through a partial laminectomy at
vertebral sections T10-L1; and the dorsal roots were carefully isolated and
cut. Four to ten days after surgery, arterial pressure and hindquarter
vascular resistance were maximally reduced by 14 +/- 2 mmHg and 42 +/- 1%,
respectively, during electrical stimulation of renal afferent fibers in
sham-operated rats. In rats with selective dorsal rhizotomy no significant
changes in arterial pressure or hindquarter vascular resistance were
observed after renal afferent nerve stimulation. Renal vasoconstrictor
responses to electrical stimulation of the left greater splanchnic nerve or
posterior hypothalamic area were not different between sham and
rhizotomized rats. These data demonstrate that severing dorsal roots T10-L1
cause a functional afferent denervation of the kidney, without impairing
renal efferent nerve function.
