Characterization of the effects of histamine on porcine
tracheobronchial lymph vessels.
Reeder, Laurie B., Vincent J. Defilippi, and Mark K. Ferguson.
From the Department of Surgery and the Section of Thoracic Surgery,
Division of the Biological Sciences, The University of Chicago,
Chicago, IL 60637
APStracts 3:0227H, 1996.
We characterized the responses of lymphatic vascular smooth muscle to
histaminergic receptor stimulation and blockade and explored the
mechanisms underlying the histamine-stimulated release of
endothelium-derived relaxing factor (EDRF). Fresh porcine
tracheobronchial lymph vessel rings mounted in organ baths were
stimulated by the cumulative addition of histamine or H1-, H2- and
H3-receptor specific agonists in the presence or absence of receptor
specific antagonists. Histamine had a contractile effect on lymphatic
vascular smooth muscle that was H1-receptor mediated. No important
effects were elicited by H2- or H3-receptor stimulation. Histamine
also caused release of EDRF as demonstrated by an increase in smooth
muscle tone in the absence of endothelium and after inhibition of
nitric oxide synthase. This effect was strong at high concentrations
of histamine and was mediated by H1-receptor stimulation. The results
suggest that histamine may contribute to the regulation of lymphatic
vascular smooth muscle tone under pathological conditions, an effect
that may be controlled through modification of H1-receptor activity.
Received 20 July 1995; accepted in final form 21 May 1996.
APS Manuscript Number H684-5.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 5 June 96