Skip Navigation

This Article
Right arrow Full Text (PDF)
Right arrow E-Letters: Submit a response to the article
Right arrow Alert me when this article is cited
Right arrow Alert me when E-letters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (16)
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by Rabadan, J. V.
Right arrow Articles by Laorden, M. L.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Rabadan, J. V.
Right arrow Articles by Laorden, M. L.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

British Journal of Anaesthesia, Vol 80, Issue 3 354-359, Copyright © 1998 by The Board of Management and Trustees of the British Journal of Anaesthesia

LABORATORY INVESTIGATIONS

Changes in right atrial catecholamine content in naive rats and after naloxone-induced withdrawal

J. V. Rabadan, M. V. Milanes and M. L. Laorden
Department of Physiology and Pharmacology, Unit of Pharmacology, University School of Medicine, Murcia, Spain

In this study, we determined if changes in heart catecholamine content during naloxone-induced withdrawal correlated with modifications in heart rate. In addition, we determined plasma concentrations of corticosterone as an index of the hypothalamo-pituitary-adrenal (HPA) axis. The effects of naloxone on norepinephrine, epinephrine or dopamine content and turnover, plasma concentrations of corticosterone and the mechanical response of the right atria of the rat were studied. Male rats were implanted with placebo or morphine pellets for 7 days. On the day of sacrifice, animals were injected with saline or naloxone 1 mg kg-1 s.c. to precipitate a withdrawal syndrome. Administration of naloxone to morphine-treated (tolerant) animals induced a decrease in atrial content of norepinephrine, epinephrine and dopamine (290.2 (11.9) ng g-1, 15.6 (2.1) ng g-1 and 9.52 (0.5) ng g-1, respectively) and an increase (1.38 (0.2) ng g-1 in the dihydroxy phenyl acetic acid/dopamine (DOPAC/DA) ratio. Administration of naloxone to morphine- treated animals enhanced plasma concentrations of corticosterone (435.8 (27.6) ng ml-1). In the isolated right atria, L-naloxone induced an increase in atrial rate in preparations from morphine-treated rats whereas in placebo-pelleted (naive) rats, L-naloxone induced a decrease. In contrast, administration of D-naloxone (inactive isomer) produced a decrease in atrial rate in preparations from placebo or morphine-treated rats. We conclude that this study has provided evidence that naloxone-induced withdrawal was characterized by activation of catecholaminergic neurones in the heart that was accompanied by an increase in atrial rate.
Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 J. Pharmacol. Exp. Ther.Home page
P. Almela, N. M. Atucha, M. V. Milanes, and M. L. Laorden
Cross-Talk between Protein Kinase A and Mitogen-Activated Protein Kinases Signalling in the Adaptive Changes Observed during Morphine Withdrawal in the Heart
J. Pharmacol. Exp. Ther., September 1, 2009; 330(3): 771 - 782.
[Abstract] [Full Text] [PDF]


Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.