AJP - Heart and Circulatory Physiology, Vol 242, Issue 2 220-H226, Copyright © 1982 by American Physiological Society
Influence of carotid sinus pressure on atrial receptors and renal blood flow
F. Karim, D. U. Mackay and C. T. Kappagoda
Stimulation of the atrial receptors results in an increase in renal blood
flow. The present investigation was undertaken to determine whether this
response was modulated by the input from the baroceptors in the carotid
sinus. The experiments were performed on dogs anesthetized with chloralose.
The systemic arterial pressure was held constant. The carotid sinuses were
perfused at 62 +/- 1.3, 95 +/- 2.7, and 145 +/- 8.3 mmHg. The atrial
receptors were stimulated by distension of small balloons positioned at the
left pulmonary vein-atrial junctions and the left atrial appendage. At a
carotid sinus pressure of 62 +/- 1.3 mmHg, the blood flow increased from
182 +/- 8.5 to 199 +/- 8.9 ml . min-1 . 100 g-1 renal mass. At a carotid
sinus pressure of 95 +/- 2.7 mmHg, the blood flow increased from 202 +/-
9.6 to 209 +/- 10.4 ml . min-1 . 100 g-1 renal mass. At a carotid sinus
pressure of 145 +/- 8.3 mmHg, the blood flow increased from 237 +/- 13.0 to
239 +/- 12.5 ml . min-1 . 100 g-1 renal mass. The first two responses alone
were statistically significant. The response at a carotid sinus pressure of
62 +/- 1.3 mmHg was abolished by cutting or cooling the cervical vagi to
8--10 degrees C. It is concluded that stimulation of the left atrial
receptors produces a reflex increase in blood flow to the kidney, and this
response is modulated by the input from the carotid sinus baroceptors.
