Alphamethyldopa analgesia: its possible mechanism of action.
The analgesic activity of alphamethyldopa (MD) was studied in mice using the acetic acid writhing test and the hot plate method. In the writhing test, MD produced a dose-dependent analgesic effect with an ED 50 of 26.5 mg/kg. The results of the hot plate test confirmed the analgesic activity of MD. Yohimbine, but not naloxone, antagonized the analgesic effect of MD in the writhing test. Atropine antagonized MD analgesia while physostigmine potentiated it. The study suggests that MD analgesia is of the nonopioid type involving both adrenergic and cholinergic systems.
D000700:Analgesics; D000818:Animals; D008297:Male; D008750:Methyldopa / Q000494:pharmacology*; D051379:Mice; D009270:Naloxone / Q000494:pharmacology; D010146:Pain / Q000503:physiopathology*; D010830:Physostigmine / Q000494:pharmacology; D011930:Reaction Time / Q000187:drug effects; D013997:Time Factors; D015016:Yohimbine / Q000494:pharmacology
D000700:Analgesics; D015016:Yohimbine; D009270:Naloxone; D008750:Methyldopa; D010830:Physostigmine