CH-38083, a selective, potent antagonist of alpha-2 adrenoceptors.

摘要: The selectivity and specificity of CH-38083 [7,8-(methylenedioxi)-14-alpha-hydroxyalloberbane HCl], a berbane derivative for alpha adrenoceptors has been studied compared with yohimbine idazoxan in peripheral tissues the central nervous system. In isolated tissue experiments was competitive antagonist at presynaptic alpha-2 on axon terminals rat vas deferens (pA2 against xylazine = 8.17 +/- 0.06) longitudinal muscle strip guinea pig ileum 8.07 0.20). As far as its postsynaptic adrenoceptor antagonistic activity is concerned affinity 4.95 0.11) l-phenylephrine rabbit pulmonary artery 5.38 0.33 l-norepinephrine) markedly less than that displayed sites. From pA2 values obtained calculated alpha-1/alpha-2 ratios yohimbine, were 4.7, 117.5 1659, respectively. failed to show any histamine muscarinic receptors it even potentiated effect serotonin atropinized ileum. It enhanced release [3H]norepinephrine from electrically stimulated mouse loaded previously labeled [3H]norepinephrine. binding studies carried out brain membrane preparations using [3H]prazosin [3H]idazoxan, (Ki alpha-1/Ki alpha-2) proved be 32.5, 289.5 1368 CH-38083, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)