Liu G Q, Han B Y, Wang E H
Zhongguo Yao Li Xue Bao. 1989 Jul;10(4):302-6.
The blocking action and selectivity of 9 tetrahydroisoquinoline alkaloids on alpha adrenoceptors have been investigated in isolated tissues. Dehydrostephanine and berbamine suppressed the inhibition of clonidine for the electrically stimulated twitch response of rat vas deferens, with pA2 values of 5.36 and 5.49, respectively. l-Crebanine, l-tetrahydrocoptisine, berberine, l-stepholidine and l-tetrahydropalmatine had obvious blocking effects on alpha 1 and alpha 2 adrenoceptors. l-Stephanine and xylopine could competitively inhibit anococcygeus muscle contraction induced by phenylephrine with pA2 values of 6.76 and 6.68, respectively. These 2 alkaloids showed no effect on the inhibition of clonidine for contractile response of rat vas deferens to field stimulation, and their selectivity ratios to block alpha 1 and alpha 2 adrenoceptors were 57.5 and 47.9, respectively. These results indicate that l-stephanine and xylopine are 2 potent and highly selective alpha 1 adrenoceptor blockers.
在离体组织中研究了9种四氢异喹啉生物碱对α肾上腺素能受体的阻断作用和选择性。脱氢千金藤碱和小檗胺抑制可乐定对大鼠输精管电刺激所致抽搐反应，其pA2值分别为5.36和5.49。左旋千金藤立定、左旋四氢黄连碱、黄连素、左旋千金藤碱和左旋四氢巴马汀对α1和α2肾上腺素能受体有明显阻断作用。左旋千金藤碱和木番荔枝碱能竞争性抑制去氧肾上腺素引起的肛门尾骨肌收缩，其pA2值分别为6.76和6.68。这2种生物碱对可乐定抑制大鼠输精管对场刺激的收缩反应无影响，其阻断α1和α2肾上腺素能受体的选择性比值分别为57.5和47.9。这些结果表明，左旋千金藤碱和木番荔枝碱是2种强效且高度选择性的α1肾上腺素能受体阻断剂。
