2-Aminoethylisothiuronium(AET)関連化合物の薬理作用(第5報) : 交感神経興奮作用を有する2-(2-Diethylaminoethyl)-1-phenylisothiuronium Bromide Hydrobromide (DEPT)のTachyphylaxis現象

抄録

Tachyphylaxis to the effects of 2-(2-diethylaminoethyl)-1-phenylisothiuronium bromide hydrobromide (DEPT), one of the 2-aminoethylisothiuronium (AET) derivatives, has been studied on the blood pressure of anesthetized rat and spinal cat, and also on the nictitating membrane of the cat. The pressor responese to DEPT declined gradually with successive injections ; the extent of tachyphylaxis induced by DEPT depended on the dosage and on the frequency of injections. But a complete depression could not be observed after 25 injections with this compound. The tachyphylaxis induced by DEPT is not crossed to tyramine or amphetamine, and is not recovered with noradrenaline infusion. Tachyphylaxis induced by tyramine in normal animals is recovered with noradrenaline infusion, but is not recovered with noradrenaline infusion after treatment with nialamide, a drug which inhibits monoamine oxidase, or large does of DEPT. In animals treated with nialamide, the tachyphylaxis induced by DEPT was similar to that in normal animals, but the tachyphylaxis to tyramine was induced more rapidly after treatment with nialamide and was similar to that produced by amphetamine in normal animals. These results mentioned above indicated that the tachyphylaxis mechanism of DEPT might be different from that of tyramine or amphetamine. Effects of reserpine, cocaine, guanethidine, bretylium, hexamethonium and tetraethylammonium to the pressor response of DEPT in urethane anesthetized rat were also investigated.