title: Non-competitive interaction between normorphine and calcium on the release of noradrenaline.
abstract: The interaction between calcium and magnesium or normorphine was studied on the electrically evoked outflow of previously incorporated [3H]noradrenaline in the isolated mouse vas deferens. The stimulation-evoked outflow of [3H]noradrenaline increased with increasing concentrations of Ca2+ ions in the medium. Mg2+ counteracted the effect of Ca2+ in a manner compatible with competitive antagonism. In contrast, normorphine interfered with the effect of Ca2+ non-competitively, thus suggesting that its mode of action differed from that of Mg2+.
mesh_terms: D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D004347:Drug Interactions; D066298:In Vitro Techniques; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009020:Morphine / Q000494:pharmacology*; D009638:Norepinephrine / Q000378:metabolism*; D014649:Vas Deferens / Q000187:drug effects / Q000378:metabolism*
chemical_list: D009020:Morphine; D008274:Magnesium; D002118:Calcium; D009638:Norepinephrine