QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Broughton, B. R. S. Articles by Donald, J. A. Search for Related Content PubMed PubMed Citation Articles by Broughton, B. R. S. Articles by Donald, J. A. Social Bookmarking                         What's this?

The Journal of Experimental Biology 205, 3093-3100 (2002)
© 2002 The Company of Biologists Limited

Nitric oxide regulation of the central aortae of the toad Bufo marinus occurs independently of the endothelium

Brad R. S. Broughton^* and John A. Donald

School of Biological and Chemical Sciences, Deakin University, Geelong, Victoria, Australia 3217

^* Author for correspondence (e-mail: brsb{at}deakin.edu.au)

Accepted 24 June 2002

Nitric oxide (NO) signalling pathways were examined in the lateral aortae and dorsal aorta of the cane toad Bufo marinus. NADPH diaphorase histochemistry and nitric oxide synthase (NOS) immunohistochemistry found no evidence for endothelial NOS in the endothelium of toad aortae, but it could be readily demonstrated in rat aorta that was used as a control. Immunohistochemistry using a specific neural NOS antibody showed the presence of neural NOS immunoreactivity in the perivascular nerves of the aortae. The anatomical data was supported by in vitro organ bath physiology, which demonstrated that the vasodilation mediated by applied acetylcholine (10^-5 mol l^-1) was not dependent on the presence of the vascular endothelium; however, it was significantly reduced in the presence of a neural NOS inhibitor, vinyl-L-NIO (10^-4 mol l^-1). In addition, atropine (10^-6 mol l^-1) (a muscarinic receptor inhibitor), L-NNA (10^-4 mol l^-1) (a NOS inhibitor) and ODQ (10^-5 mol l^-1) (an inhibitor of soluble guanylyl cyclase) abolished the vasodilatory effect of applied acetylcholine. In conclusion, we propose that an endothelial NO system is absent in toad aortae and that NO generated by neural NOS in perivascular nerves mediates vasodilation.

Key words: nitric oxide, endothelial nitric oxide synthase, neural nitric oxide synthase, soluble guanylyl cyclase, vasodilation, aorta, cane toad, Bufo marinus

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				B. L. Jennings and J. A. Donald Neurally-derived nitric oxide regulates vascular tone in pulmonary and cutaneous arteries of the toad, Bufo marinus Am J Physiol Regulatory Integrative Comp Physiol, November 1, 2008; 295(5): R1640 - R1646. [Abstract] [Full Text] [PDF]

				B. R. S. Broughton and J. A. Donald Dual mechanisms for nitric oxide control of large arteries in the estuarine crocodile Crocodylus porosus J. Exp. Biol., January 1, 2007; 210(1): 129 - 137. [Abstract] [Full Text] [PDF]

				B. L. Jennings, B. R. S. Broughton, and J. A. Donald Nitric oxide control of the dorsal aorta and the intestinal vein of the Australian short-finned eel Anguilla australis J. Exp. Biol., March 15, 2004; 207(8): 1295 - 1303. [Abstract] [Full Text] [PDF]