title: An analog of ACTH/MSH (4-9), ORG-2766, reduces cerebral uptake of morphine.
abstract: The uptake of morphine was significantly reduced in most regions of the brains of conscious, unrestrained rats within 10 minutes after treatment with an analog of ACTH/MSH (4-9), ORG-2766. The effect was most obvious in regions with significant densities of enkephalin receptors, namely basal ganglia, hippocampus and cortex. The results explain, in part, how some fragments and analogs of ACTH/MSH may antagonize behavioral actions of morphine, even though some of these peptides lack significant opiate receptor binding properties. We believe that this effect of ORG-2766 is related to an action on the permeability characteristics of the brain microvasculature. The underlying mechanism is unknown.
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D001479:Basal Ganglia / Q000378:metabolism; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D002199:Capillary Permeability; D002540:Cerebral Cortex / Q000378:metabolism; D002560:Cerebrovascular Circulation / Q000187:drug effects; D006624:Hippocampus / Q000378:metabolism; D007031:Hypothalamus / Q000378:metabolism; D009020:Morphine / Q000378:metabolism*; D010446:Peptide Fragments / Q000494:pharmacology*; D051381:Rats
chemical_list: D010446:Peptide Fragments; C013765:Org 2766; D009020:Morphine; D000324:Adrenocorticotropic Hormone