AJP - Regulatory, Integrative and Comparative Physiology, Vol 253, Issue 3
494-R500, Copyright © 1987 by American Physiological Society
Articles by Haxhiu, M. A.
Articles by Cherniack, N. S.
A role for the ventral surface of the medulla
in regulation of nasal resistance
M. A. Haxhiu, K. P. Strohl, M. P. Norcia, E. van Lunteren,
E. C. Deal Jr and N. S. Cherniack
Nasal resistance is known to be affected by changes in nasal blood volume
and hence to depend on sympathetic discharge to nasal blood vessels.
Structures located superficially near the ventrolateral surface of the medulla
significantly affect respiratory and sympathetic activity and the tone of the
trachea. To assess the importance of these structures on nasal patency, we
measured transnasal pressure at a constant flow and examined the change in
pressure produced by topically applied N-methyl-D-aspartic acid (NMDA).
Experiments were performed in chloralose-anesthetized, paralyzed, and
artificially ventilated cats. NMDA administered on the intermediate area of
the ventral surface of the medulla decreased transnasal pressure and increased phrenic nerve activity. The response to
NMDA could be diminished or abolished by application to the ventral medullary surface of the NMDA antagonist
2-amino-5-phosphonovalerate (2-APV) or the local anesthetic lidocaine. Carotid sinus denervation and
posthypothalamic decerebration did not alter the nasal and phrenic nerve responses to NMDA; however, cervical
sympathetic denervation decreased these responses, both in intact and in bilaterally adrenalectomized animals. Therefore,
activation of NMDA receptors on structures near the ventral surface of the medulla increases tone in the nasal
vasculature and leads to a response pattern that includes changes in not only phrenic nerve activity and blood pressure
but also nasal patency.
