Effects of narcotic analgesics on serotonin metabolism in brain of rats and mice.
The effects of narcotic analgesics on the brain 5-hydroxytryptamine (5-Ht) and 5-hydroxyindoleacetic acid (5-HIAA) levels of rats and mice were investigated in relation to our preceding data on the effect of humoral modulatorents. The results suggest that morphine accelerates the release of brain 5-HT both in rats and mice, and that neither methadone nor pethidine alters the brain 5-HT and 5-HIAA levels in rats. The morphine-induced increase in brain 5-HT turnover is likely to be involved in the morphine-induced decrease in locomotor activity and hypothermia in rats. The activity-decreasing effects of methadone or pethidine, on the other hand, are mediated by mechanisms different from those which mediate the effects of morphine. In contrast, an increase in brain 5-HT turnover in mice apparently does not play an important role on activity-increasing effects of morphine but rather participates in other pharmacological effects of morphine.
D000701:Analgesics, Opioid / Q000494:pharmacology*; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D004347:Drug Interactions; D010134:Fenclonine / Q000494:pharmacology; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D008297:Male; D008614:Meperidine / Q000494:pharmacology; D008691:Methadone / Q000494:pharmacology; D051379:Mice; D008813:Mice, Inbred ICR; D009020:Morphine / Q000494:pharmacology; D009270:Naloxone / Q000494:pharmacology; D010293:Pargyline / Q000494:pharmacology; D011339:Probenecid / Q000494:pharmacology; D051381:Rats; D012701:Serotonin / Q000378:metabolism*
D000701:Analgesics, Opioid; D012701:Serotonin; D009270:Naloxone; D006897:Hydroxyindoleacetic Acid; D009020:Morphine; D001285:Atropine; D008614:Meperidine; D010293:Pargyline; D011339:Probenecid; D010134:Fenclonine; D008691:Methadone