AJP - Heart and Circulatory Physiology, Vol 244, Issue 1 55-H59, Copyright © 1983 by American Physiological Society
Intravascular receptors and renal responses of monkey to volume expansion
T. V. Peterson, F. T. Felts and N. L. Chase
Experiments were performed in anesthetized Macaca fascicularis monkeys to
determine the effects of combined thoracic dorsal rhizotomy (C8-T7) and
vagotomy-sinoaortic denervation on the renal responses to acute
intravascular volume expansion. Expansion of the estimated blood volume by
15% with 6% dextran in isotonic saline produced attenuated diuretic and
natriuretic responses in the denervated animals when compared with
sham-operated controls. The times to peak diuresis and natriuresis after
volume expansion also were significantly earlier in the denervated group.
Although central venous pressure increased similarly in both groups, mean
arterial pressure increased to a greater extent after volume expansion in
the denervated group. As opposed to the previously reported failure of
either denervation alone to attenuate the renal responses to hypervolemia
in the monkey, our results suggest that these neural pathways may play a
role in maintaining salt and water balance in this species. However,
because of the possibility of functionally redundant afferent mechanisms,
blunted renal responses to volume expansion in the primate can only be
demonstrated after an extensive denervation.
