Journal of Applied Physiology, Vol 46, Issue 1 84-88, Copyright © 1979 by American Physiological Society
Pulmonary hemodynamic responses to elevated cerebral spinal fluid pressure in the dog
M. B. Maron, T. S. Hakim and C. A. Dawson
To investigate the possibility that a pulmonary vasomotor reflex
contributes to the pulmonary hemodynamic response to elevated cerebral
spinal fluid pressure (PCSF), we studied 10 chloralose-anesthetized dogs in
which the left lower lobe (LLL) perfusion was isolated to eliminate the
influence of passive factors and of circulating vasoactive agents. Left
lower lobe neural integrity was tested by electrically stimulating the
stellate ganglion. This resulted in a 35.5% increase in lobar vascular
resistance and a 29.1% increase in systemic vascular resistance. Elevating
the PCSF to 137 Torr caused the systemic vascular resistance to increase
33.0%, but resulted in no change in LLL vascular resistance. In the intact
right lung, this PCSF elevation resulted in increases in pulmonary artery
and left atrial pressures, but no change in right lung vascular resistance.
Because the neurally intact LLL did not respond to PCSF elevation and the
responses of the right lung could be accounted for by passive mechanisms,
we conclude that no pulmonary vascular reflex was elicited by PCSF
elevation in this preparation.
