Inability of naloxone to change brain morphine levels in tolerant mice

European Journal of Pharmacology
J DumD H Catlin


The effect of naloxone on brain morphine concentrations was measured in naive and morphine-dependent mice using radioimmunoassay and gas-liquid chromatography. No displacement of morphine from the brain by naloxone could be observed in naive mice acutely injected with morphine or in pellet-implanted mice at increasing intervals after removal of the morphine pellets. The suggestion of a change in affinity of opiate receptors during the development of tolerance/dependence, which had been made on the basis of the displacement of morphine by naloxone found by other workers, is thus not supported by the present results.


Jan 1, 1976·Annals of the New York Academy of Sciences·E L Way, H H Loh
Jun 12, 1970·Science·S Spector, C W Parker


Aug 1, 1978·European Journal of Pharmacology·H N Bhargava
May 15, 1979·European Journal of Pharmacology·J DumA Herz
Oct 15, 1979·European Journal of Pharmacology·J DumA Herz

Related Concepts

Chromatography, Gas-Liquid
Drug Tolerance
Morphine Sulfate (2: 1), Pentahydrate
Naloxone, (5 beta,9 alpha,13 alpha,14 alpha)-Isomer
Mouse, Swiss

Trending Feeds


Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Genetic Screens in iPSC-derived Brain Cells

Genetic screening is a critical tool that can be employed to define and understand gene function and interaction. This feed focuses on genetic screens conducted using induced pluripotent stem cell (iPSC)-derived brain cells. It also follows CRISPR-Cas9 approaches to generating genetic mutants as a means of understanding the effect of genetics on phenotype.

Alzheimer's Disease: MS4A

Variants within the membrane-spanning 4-domains subfamily A (MS4A) gene cluster have recently been implicated in Alzheimer's disease in genome-wide association studies. Here is the latest research on Alzheimer's disease and MS4A.

Pediculosis pubis

Pediculosis pubis is a disease caused by a parasitic insect known as Pthirus pubis, which infests human pubic hair, as well as other areas with hair including eye lashes. Here is the latest research.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Rh Isoimmunization

Rh isoimmunization is a potentially preventable condition that occasionally is associated with significant perinatal morbidity or mortality. Discover the latest research on Rh Isoimmunization here.

Pharmacology of Proteinopathies

This feed focuses on the pharmacology of proteinopathies - diseases in which proteins abnormally aggregate (i.e. Alzheimer’s, Parkinson’s, etc.). Discover the latest research in this field with this feed.

Enzyme Evolution

This feed focuses on molecular models of enzyme evolution and new approaches (such as adaptive laboratory evolution) to metabolic engineering of microorganisms. Here is the latest research.

Alignment-free Sequence Analysis Tools

Alignment-free sequence analyses have been applied to problems ranging from whole-genome phylogeny to the classification of protein families, identification of horizontally transferred genes, and detection of recombined sequences. Here is the latest research.