Enkephalin levels decrease in rat striatum during morphine abstinence.
Male Sprague-Dawley rats were treated with morphine for 11 days. Saline-injected animals served as controls. The striatal enkephalin levels were measured with a radioimmunoassay 2, 24 and 48 h after withdrawal. There was no change 2 h after the last morphine injection, but a marked reduction after 24 h and a slight decrease after 48 h. No decrease in enkephalin levels was found 12 and 24 h after a single dose of 20 mg/kg morphine.
D000818:Animals; D000917:Antibody Formation; D000937:Antigen-Antibody Reactions; D003342:Corpus Striatum / Q000378:metabolism*; D004723:Endorphins / Q000378:metabolism*; D004745:Enkephalins / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D008297:Male; D009021:Morphine Dependence / Q000378:metabolism*; D011817:Rabbits / Q000276:immunology; D051381:Rats; D013375:Substance Withdrawal Syndrome / Q000378:metabolism*; D013997:Time Factors
D004723:Endorphins; D004745:Enkephalins