AJP - Heart and Circulatory Physiology, Vol 246, Issue 3 319-H323, Copyright © 1984 by American Physiological Society
Sustained interruption of the aortic baroreflex by left cervical vagotomy in dogs
S. C. Walgenbach
Previous experiments demonstrated that acute left vagotomy interrupted 90%
of the aortic baroreflex. The present study determined whether or not this
interruption was sustained over a period of weeks. Bilateral carotid
occlusions (BCO) were performed in conscious dogs before and for 3 wk after
left vagotomy and immediately after subsequent right vagotomy. Prior to
left vagotomy, BCO induced a rise in arterial pressure of 28 +/- 8 mmHg but
no change in heart rate. After left vagotomy, BCO resulted in a rise in
arterial pressure of 71 +/- 7 mmHg and a rise in heart rate of 43 +/- 6
beats/min. The BCO-induced elevations in arterial pressure and heart rate
did not change significantly during the next 3 wk. Subsequent right
vagotomy did not alter the rise in arterial pressure to BCO. These data
indicate that left cervical vagotomy interrupts the aortic baroreflex for
at least a 3-wk period and suggest that this procedure, when combined with
reversible vascular isolation of the carotid sinuses, provides a method for
studying cardiovascular adaptation to the acute loss of sinoaortic reflexes
in the conscious dog.
