[On the pharmacology of the alpha-receptor blocker BE 2254 (HEAT) (author's transl)].

The alpha-adrenolytic activity of BE 2254 was investigated in in vitro as well as in vivo assays. On the isolated rat anococcygeus muscle, 2-[beta-(4-hydroxyphenyl)-ethyl-amino-methyl]tetralone(1) (BE 2254) shows a high affinity for postsynaptic alpha-adrenoceptors (pA2 = 8.9), in contrast to its much weaker potency (pA2 = 6.7) in inhibiting clonidine on the electrically driven rat vas deferens, thus suggesting a relative preference for postsynaptic alpha-adrenoceptors. BE 2254 effects on other catecholamine receptors are either negligible or not detectable. The hypotensive action of BE 2254 is shown to be solely due to alpha-blockade. All alpha-adrenolytic actions studied were of competitive nature.