AJP - Regulatory, Integrative and Comparative Physiology, Vol 245, Issue 2 251-R258, Copyright © 1983 by American Physiological Society
Neural control of renal excretory function during behavioral stress in conscious dogs
J. P. Koepke, K. C. Light and P. A. Obrist
The renal and neural mechanisms underlying the excretory response to
behavioral stress (aversive conditioning) were examined in 30 conscious
dogs. Twenty-one dogs decreased urine flow more than 20% during stress,
whereas 9 dogs showed less than a 10% decrease. In 11 of the 21
renal-reactive dogs, decreases in urine flow (42%) and sodium excretion
(45%) were associated with unchanged glomerular filtration (-1.5%; GFR;
inulin clearance) and effective renal blood flow (-4%; RBF;
p-aminohippurate clearance). In the other 10 renal-reactive dogs, similar
declines in urine flow (54%) and sodium excretion (52%) occurred with
decreases in GFR (24%) and RBF (27%). Among all 30 dogs, greater increases
in cardiovascular activity during stress were associated with greater
decreases in renal excretion. Surgical renal denervation abolished the
excretory response to stress in 4 of 5 dogs. These findings suggest that
excretory responses in most dogs are mediated 1) primarily via increased
tubular reabsorption rather than decreased GFR, 2) via central integration
with cardiovascular responses, and 3) via the renal nerves.
