Cyclazocine and norepinephrine uptake, metabolism, and turnover in the rat brain.
The effects of cyclazocine, a narcotic agonist/antagonist, on the uptake, metabolism, and turnover of norepinephrine in rat brains were studied. Cyclazocine significantly depressed the accumulation of intracisternally administered [3H]norepinephrine and the formation of 3,4-[3H]dihydroxymandelic acid but did not alter the formation of [3H]-normetanephrine. Comparatively, imipramine reduced the uptake of [3H]norepinephrine, decreased the formation of 3,4-[3H]dihydroxymandelic acid, and increased the formation of [3H]normetanephrine. Moreover, cyclazocine increased the formation of endogenous 3-methoxy-4-hydroxyphenylethylene glycol and produced a fall in endogenous norepinephrine. It is suggested that cyclazocine reduces the accumulation of [3H]norepinephrine, decreases endogenous norepinephrine levels, and increases the formation of 3-methoxy-4-hydroxyphenylethylene glycol by interacting with brain adrenergic nerves, presumably by inhibiting neuronal uptake and facilitating norepinephrine turnover.
D000818:Animals; D001921:Brain / Q000378:metabolism*; D002395:Catecholamines / Q000378:metabolism; D003496:Cyclazocine / Q000494:pharmacology*; D007099:Imipramine / Q000494:pharmacology; D008297:Male; D008333:Mandelic Acids / Q000378:metabolism; D008734:Methoxyhydroxyphenylglycol / Q000378:metabolism; D009638:Norepinephrine / Q000378:metabolism*; D009647:Normetanephrine / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013050:Spectrometry, Fluorescence
D002395:Catecholamines; D008333:Mandelic Acids; D009647:Normetanephrine; D008734:Methoxyhydroxyphenylglycol; C000989:3,4-dihydroxymandelic acid; D003496:Cyclazocine; D007099:Imipramine; D009638:Norepinephrine