Biphasic effects of a potent enkephalin analogue (D-Met2,Pro5)-enkephalinamide and morphine on locomotor activity in mice.
The effects of morphine and a potent enkephalin analogue on spontaneous locomotion have been compared in mice. In doses of 3-10 mg/kg SC both compounds induced a brief reduction of motor activity followed by a period of behavioral hyperactivity. Similar receptorial mechanisms are suggested in mediation of their motor effects.
D000818:Animals; D004305:Dose-Response Relationship, Drug; D004723:Endorphins / Q000494:pharmacology*; D004744:Enkephalin, Methionine / Q000031:analogs & derivatives*; D004745:Enkephalins / Q000494:pharmacology*; D008297:Male; D051379:Mice; D009020:Morphine / Q000494:pharmacology*; D009043:Motor Activity / Q000187:drug effects*; D013997:Time Factors
D004723:Endorphins; D004745:Enkephalins; D004744:Enkephalin, Methionine; C021717:enkephalin, Met(2)-ProNH2(5)-; D009020:Morphine