Naloxone prevention of morphine LDR curve flattening associated with high-dose tolerance
- 1 November 1981
- journal article
- research article
- Published by Springer Nature in Psychopharmacology
- Vol. 75 (2), 132-133
- https://doi.org/10.1007/bf00432174
Abstract
Male wistar rats, previously made tolerant to morphine by at least 3 weeks of daily intraperitoneal (IP) injections of 20 mg/kg morphine-SO4 (MS), were then given 200 mg/kg MS daily for 4 or 5 days. Tail immersion tests of antinociception, carried out before and after the 200 mg/kg MS treatment, indicated that the additional morphine treatment was followed by a large further decrease in opiate sensitivity, characterized by decreased slope of the log-dose/response curve (LDR curve flattening). The further decrease in opiate sensitivity was substantially reduced by naloxone-HCl (IP) in a dose of 10 mg/kg given 30 min before and 8 h after the 200 mg/kg MS injections, or a dose of 4 mg/kg given 45 min after the MS. It was concluded that LDR curve flattening produced by high doses of MS is mediated by specific opiate receptors, and is a true expression of a high degree of opiate tolerance in the intact rat.This publication has 6 references indexed in Scilit:
- Log dose/response curve flattening in rats after daily injection of opiatesPsychopharmacology, 1980
- Quantitative relationships among measures of morphine tolerance and physical dependence in the ratPharmacology Biochemistry and Behavior, 1979
- INHIBITION BY NALOXONE OF TOLERANCE AND DEPENDENCE IN MICE TREATED ACUTELY AND CHRONICALLY WITH MORPHINE1977
- Tolerance to morphine in the rat: Its prevention by naloxoneLife Sciences, 1976
- KINETIC PARAMETERS OF NARCOTIC AGONISTS AND ANTAGONISTS, WITH PARTICULAR REFERENCE TO N‐ALLYLNOROXYMORPHONE (NALOXONE)British Journal of Pharmacology and Chemotherapy, 1968
- THE EFFECT OF N-ALLYLNORMORPHINE UPON THE DEVELOPMENT OF TOLERANCE TO MORPHINE IN THE ALBINO RAT1953