Macrovascular dopamine release.
Kraschinski, Stephanie, August Epple, and Barbara Nibbio.
Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson
University, Philadelphia, PA 19107
APStracts 3:0006R, 1996.
In an animal model, the American eel, perifused elastic arteries and
large veins, but not the heart and organs with extensive
microvascular supply (gills and opisthonephric kidney), release
spontaneously free dopamine (DA). Only the region of the cardinal
vein which contains the adrenomedullary equivalent, also releases
norepinephrine (NE) and epinephrine (E). Ca++, KCl and E stimulate DA
release from the ventral aorta and caudal vein, indicating that this
phenomenon is due to secretion, and not to wash-out. E also
stimulates NE release from the ventral aorta and caudal vein. In the
rat, both aorta and vena cava release spontaneously DA and NE. Thus,
DA secretion from large blood vessels may be general in vertebrates.
The DA response to high physiological concentrations of E in vivo and
in vitro suggests that macrovascular DA may be involved in local
stress responses.
Received 26 June 1995; accepted in final form 13 December 1995.
APS Manuscript Number R390-5.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 22 January 96