Peptidergic control of gastrointestinal blood flow in the estuarine crocodile, Crocodylus porosus

Kagstrom, J., Olsson, C., Axelsson, M. and Franklin, C. E. (1998) Peptidergic control of gastrointestinal blood flow in the estuarine crocodile, Crocodylus porosus. American Journal of Physiology-regulatory Integrative And Comparative Physiology, 274 6: R1740-R1750.

Author Kagstrom, J.
Olsson, C.
Axelsson, M.
Franklin, C. E.
Title Peptidergic control of gastrointestinal blood flow in the estuarine crocodile, Crocodylus porosus
Journal name American Journal of Physiology-regulatory Integrative And Comparative Physiology   Check publisher's open access policy
ISSN 0363-6119
1522-1490
Publication date 1998-01-01
Sub-type Article (original research)
Volume 274
Issue 6
Start page R1740
End page R1750
Total pages 11
Place of publication United States
Publisher American Physiological Society
Language eng
Abstract Peptidergic mechanisms influencing the resistance of the gastrointestinal vascular bed of the estuarine crocodile, Crocodylus porosus, were investigated. The gut was perfused in situ via the mesenteric and the celiac arteries, and the effects of different neuropeptides were tested using bolus injections. Effects on vascular resistance were recorded as changes in inflow pressures. Peptides found in sensory neurons [substance P, neurokinin A, and calcitonin gene-related peptide (CGRP)] all caused significant relaxation of the celiac vascular bed, as did vasoactive intestinal polypeptide (VIP), another well-known vasodilator. Except for VIP, the peptides also induced transitory gut contractions. Somatostatin and neuropeptide Y (NPY), which coexist in adrenergic neurons of the C. porosus, induced vasoconstriction in the celiac vascular bed without affecting the gut motility. Galanin caused vasoconstriction and occasionally activated the gut wall. To elucidate direct effects on individual vessels, the different peptides were tested on isolated ring preparations of the mesenteric and celiac arteries. Only CGRP and VIP relaxed the epinephrine-precontracted celiac artery, whereas the effects on the mesenteric artery were variable. Somatostatin and NPY did not affect the resting tonus of these vessels, but somatostatin potentiated the epinephrine-induced contraction of the celiac artery. Immunohistochemistry revealed the existence and localization of the above-mentioned peptides in nerve fibers innervating vessels of different sizes in the gut region. These data support the hypothesis of an important role for neuropeptides in the control of the vascular bed of the gastrointestinal tract in C. porosus.
Keyword Physiology
Sensory Neurotransmitters
Somatostatin
Vasoactive Intestinal Polypeptide
Gut Circulation
Reptiles
Gene-related Peptide
Substance-p
Smooth-muscle
Alligator-mississipiensis
Autonomic Nerves
Neuropeptide-y
Nervous-system
Atlantic Cod
Gadus-morhua
Somatostatin
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Unknown

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Biological Sciences Publications
Ecology Centre Publications
 
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Created: Mon, 13 Aug 2007, 20:29:00 EST