Effects of adrenoceptor antagonists and neuronal uptake inhibitors on dimethylphenylpiperazinium-induced release of catecholamines from the rabbit isolated adrenal gland and guinea-pig atria

摘要: Isolated rabbit adrenal glands were perfused with Krebs-Henseleit solution at 37 degrees C and the catecholamine storage sites labeled [3H]epinephrine. Release of radioactivity was evoked by 2-min periods perfusion dimethylphenylpiperazinium (DMPP, 100 microM). DMPP-induced efflux decreased desipramine (1 microM), cocaine (30 phenoxybenzamine 10 phentolamine (1, 3 microM) propranolol The reduction in cannot be accounted for interactions alpha adrenoceptors, as prazosin yohimbine without effect. There also no correlation between inhibition ability drugs to inhibit uptake did not affect incorporation [3H]epinephrine gland. In guinea-pig atria, which had been [3H]norepinephrine, elicited 1-min contact DMPP. from atria but or could correlated adrenoceptor antagonism blockade neuronal uptake. differences two preparations degree release produced above drugs.(ABSTRACT TRUNCATED AT 250 WORDS)