Chronic treatment with ascorbic acid inhibits the morphine withdrawal response in guinea-pigs.
The effects of ascorbic acid (AA) were investigated on the morphine withdrawal response of guinea-pigs, a species which shares with man the inability to synthesize AA. Chronic pretreatment of guinea-pigs with AA, 1 g/l, in drinking water for 3 days, or AA 200 mg/kg subcutaneously (s.c.) 3 times daily for 3 days, markedly reduced the locomotor and behavioural withdrawal responses of guinea-pigs given naloxone hydrochloride, 15 mg/kg s.c. 2 h after a single dose of morphine sulphate, 15 mg/kg s.c. AA, 1 g/kg given intraperitoneally (i.p.) 30 min before morphine had no significant effect on morphine withdrawal. However, intracerebroventricular injection of AA, 1 mumol, 30 min before naloxone significantly enhanced morphine withdrawal. It is concluded that chronic but not acute administration of AA inhibits opiate withdrawal.
Johnston
P A
PA
Neuropharmacology Laboratory, Faculty of Medicine, University of Newcastle, N.S.W., Australia.
Chahl
L A
LA
D000818:Animals; D001205:Ascorbic Acid / Q000494:pharmacology*; D004334:Drug Administration Schedule; D005260:Female; D006168:Guinea Pigs; D008297:Male; D009020:Morphine / Q000008:administration & dosage; D009021:Morphine Dependence / Q000503:physiopathology*; D009043:Motor Activity / Q000187:drug effects*; D009270:Naloxone / Q000494:pharmacology; D013239:Stereotyped Behavior / Q000187:drug effects*; D013375:Substance Withdrawal Syndrome / Q000503:physiopathology*
D009270:Naloxone; D009020:Morphine; D001205:Ascorbic Acid