JPET xPharm- The Comprehensive Pharmacology Reference

Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text (PDF)
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Chakder, S.
Right arrow Articles by Rattan, S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Chakder, S.
Right arrow Articles by Rattan, S.

Neurally mediated relaxation of opossum internal anal sphincter: influence of superoxide anion generator and the scavenger

S Chakder and S Rattan

Jefferson Medical College, Thomas Jefferson University, Department of Medicine, Philadelphia, Pennsylvania.

The present investigation was undertaken to examine the influence of super oxide anion generator hydroquinone and the superoxide anion scavenger superoxide dismutase (SOD) on the neurally mediated relaxation of the internal and sphincter (IAS). The studies were performed in vitro on IAS smooth muscle strips of opossums. Neural stimulation with appropriate parameters of electrical field stimulation is known to cause IAS relaxation by the activation of nonadrenergic noncholinergic inhibitory neurons. Hydroquinone caused a concentration- dependent suppression of IAS relaxation in response to neural stimulation. The suppression of the IAS relaxation was reversed by SOD in a concentration-dependent manner. The fall in the IAS tension by nitric oxide (NO) was also suppressed by hydroquinone and reversed by SOD. SOD alone caused an augmentation of the fall in the IAS tension by NO. The fall in the IAS tension in response to the candidate inhibitory neurotransmitter vasoactive intestinal polypeptide was not modified by SOD in the basal state. Hydroquinone, however, caused a significant suppression of vasoactive intestinal polypeptide-induced fall in the IAS tension which was reversed by SOD. The fall in the resting IAS tension by the directly acting smooth muscle relaxants, beta adrenoceptor agonist isoproterenol and atrial natriuretic factor were not significantly modified by hydroquinone or SOD. From the present data we conclude: NO or an NO-like factor plays a significant role in the nonadrenergic noncholinergic nerve-mediated IAS relaxation.

Volume 260, Issue 3, pp. 1113-1118, 03/01/1992
Copyright © 1992 by American Society for Pharmacology and Experimental Therapeutics




This article has been cited by other articles:


Home page
 Am. J. Respir. Crit. Care Med.Home page
J. DE BOER, F.M. H. POUW, J. ZAAGSMA, and H. MEURS
Effects of Endogenous Superoxide Anion and Nitric Oxide on Cholinergic Constriction of Normal and Hyperreactive Guinea Pig Airways
Am. J. Respir. Crit. Care Med., December 1, 1998; 158(6): 1784 - 1789.
[Abstract] [Full Text] [PDF]


Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
All ASPET Journals Molecular Pharmacology Pharmacological Reviews
Molecular Interventions Drug Metabolism and Disposition

Copyright © 1992 by the American Society for Pharmacology and Experimental Therapeutics.