JPET

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 Winters, W. D.
Right arrow Articles by Benthuysen, J. L.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Winters, W. D.
Right arrow Articles by Benthuysen, J. L.

Ketamine- and morphine-induced analgesia and catalepsy. I. Tolerance, cross-tolerance, potentiation, residual morphine levels and naloxone action in the rat

WD Winters, AJ Hance, GG Cadd, DD Quam and JL Benthuysen

Department of Pharmacology, School of Medicine, University of California, Davis.

The effects of ketamine and morphine on pain perception and catalepsy were compared in rats. Analgesia, as measured by the latency to withdrawal of the tail from a 55 degrees C water bath (tail-flick latency difference, TFLD), was produced by both ketamine and morphine, but at widely different doses, and in each case the effect was reversed by naloxone. Catalepsy, measured by the duration of loss of righting reflex (DLRR) in catatonic animals, was induced by larger doses of both ketamine and morphine and in each case was reduced by a larger dose of naloxone. DLRR and TFLD tolerance developed rapidly and with a similar time course after daily doses of ketamine or morphine. Rats tolerant to the DLRR effect of ketamine showed cross-tolerance to morphine. Rats tolerant to the DLRR effect of morphine did not show cross-tolerance to ketamine when administered the following day; instead, these rats showed potentiation of the ketamine-induced DLRR. The degree of potentiation noted 24 hr after a single or multiple daily doses of 45 mg/kg of morphine is the same as that seen when 2 mg/kg of morphine is given simultaneously with ketamine. The residual brain level of morphine 24 hr after 45 mg/kg is similar to the level 1 hr after a 2- mg/kg dose. The augmented ketamine response in morphine-tolerant rats is postulated to be a result of residual morphine still present in the brain 24 hr after the last DLRR-inducing dose of morphine.(ABSTRACT TRUNCATED AT 250 WORDS)

Volume 244, Issue 1, pp. 51-57, 01/01/1988
Copyright © 1988 by American Society for Pharmacology and Experimental Therapeutics




This article has been cited by other articles:


Home page
 J PsychopharmacolHome page
B. A. Chizh
Low dose ketamine: a therapeutic and research tool to explore N-methyl-D-aspartate (NMDA) receptor-mediated plasticity in pain pathways
J Psychopharmacol, May 1, 2007; 21(3): 259 - 271.
[Abstract] [PDF]

Home page
 J. Neurosci.Home page
K. Gao, D. O. Chen, J. R. Genzen, and P. Mason
Activation of Serotonergic Neurons in the Raphe Magnus Is Not Necessary for Morphine Analgesia
J. Neurosci., March 1, 1998; 18(5): 1860 - 1868.
[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 © 1988 by the American Society for Pharmacology and Experimental Therapeutics.