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Mechanisms of vasodilation in the dorsal aorta of the elephant fish, Callorhinchus milii (Chimaeriformes: Holocephali)


Jennings, BL and Bell, JD and Hyodo, S and Toop, T and Donald, JA, Mechanisms of vasodilation in the dorsal aorta of the elephant fish, Callorhinchus milii (Chimaeriformes: Holocephali), Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology, 177, (5) pp. 557-567. ISSN 0174-1578 (2007) [Refereed Article]

DOI: doi:10.1007/s00360-007-0154-7


This study investigated vasodilator mechanisms in the dorsal aorta of the elephant fish, Callorhinchus milii, using anatomical and physiological approaches. Nitric oxide synthase could only be located in the perivascular nerve fibres and not the endothelium of the dorsal aorta, using NADPH histochemistry and immunohistochemistry. In vitro organ bath experiments demonstrated that a NO/soluble guanylyl cyclase (GC) system appeared to be absent in the vascular smooth muscle, since the NO donors SNP (10-4 mol l-1) and SIN-1 (10-5 mol l-1) were without effect. Nicotine (3 × 10-4 mol l-1) mediated a vasodilation that was not affected by ODQ (10-5 mol l-1), l-NNA (10-4 mol l-1), indomethacin (10-5 mol l-1), or removal of the endothelium. In contrast, the voltage-gated sodium channel inhibitor, tetrodotoxin (10-5 mol l-1), significantly decreased the dilation induced by nicotine, suggesting that it contained a neural component. Pre-incubation of the dorsal aorta with the calcitonin gene-related peptide (CGRP) receptor antagonist, CGRP8-37 (10-6 mol l-1) also caused a significant decrease in the nicotine-induced dilation. We propose that nicotine is mediating a neurally-derived vasodilation in the dorsal aorta that is independent of NO, prostaglandins and the endothelium, and partly mediated by CGRP. © 2007 Springer-Verlag.

Item Details

Item Type:Refereed Article
Keywords:Calcitonin gene-related peptide; Holocephalan; Nitric oxide; Nitric oxide synthase; Prostaglandin; Vasodilation; calcitonin gene related peptide; calcitonin gene related peptide (8 37); calcitonin gene related peptide receptor; nicotine; animal; rat
Research Division:Agricultural, Veterinary and Food Sciences
Research Group:Fisheries sciences
Research Field:Fish physiology and genetics
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the biological sciences
UTAS Author:Bell, JD (Dr Justin Bell)
ID Code:82511
Year Published:2007
Web of Science® Times Cited:9
Deposited By:Sustainable Marine Research Collaboration
Deposited On:2013-02-06
Last Modified:2013-06-06

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