Effects of morphine on noradrenaline release from cerebral and peripheral vascular smooth muscle.
Morphine reduced the [3H]noradrenaline uptake in cat cerebral and femoral arteries and induced a dose-dependent tritium release from these vessels prelabelled with this amine, which was diminished in Ca2+-free medium. The opioid decreased the radioactivity release induced by electrical field stimulation as well as its potentiation by tetraethylammonium. These effects were unaffected by naloxone. These results indicate: the reduction by morphine of tritium release from both kinds of vessels is through a mechanism unrelated to opiate receptors, and the noradrenaline release elicited by morphine could be due in part to inhibition of its reuptake.
D000818:Animals; D001921:Brain / Q000378:metabolism*; D002415:Cats; D004558:Electric Stimulation; D005260:Female; D005263:Femoral Artery / Q000378:metabolism; D066298:In Vitro Techniques; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism*; D009270:Naloxone / Q000494:pharmacology; D009638:Norepinephrine / Q000378:metabolism*; D013757:Tetraethylammonium Compounds / Q000494:pharmacology
D013757:Tetraethylammonium Compounds; D009270:Naloxone; D009020:Morphine; D009638:Norepinephrine