Vagal neuroeffector mechanisms affecting transpulmonary pressure in
the intact rat.
Haselton, James R., Andrew Y. Reynolds, and Harold D. Schultz.
Department of Physiology and Biophysics, University of Nebraska
Medical Center, 600 South 42 Street, Omaha, NE 68198-4575
APStracts 2:0230A, 1995.
Studies were conducted to determine if vagal activation in the intact
anesthetized rat elicits airways smooth muscle responses attributable
to non-adrenergic, non-cholinergic transmitters. Transpulmonary
pressure (Ptr) was used as an index of airways smooth muscle tone,
and the peak inspiratory Ptr (peak Ptr) values were used for
comparison of responses. Experiments were conducted with chloralose
-urethane-anesthetized rats to assess the effects of: 1) bilateral
stimulation of the cervical vagus nerves, and 2) parasympathomimetic
and sympathomimetic agents. As expected, in untreated animals
bilateral stimulation of the vagus nerves elicited an increase in
peak Ptr of 155% (from 7.5 + 0.4 cm H2O to 11.6 + 1.2 cm H2O). The
magnitude of the response was greatest when the stimulus frequency
was >/= 40 Hz, and with stimulus pulse durations >/= 0.1 ms but
Received 10 June 1994; accepted in final form 16 may 1995.
APS Manuscript Number A574-4.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 30 May 1995.