Lu Z Z, Wei X, Jin G Z, Han Q D
Institute of Vascular Medicine, Third Hospital, Beijing Medical University.
Yao Xue Xue Bao. 1996;31(9):652-6.
The antagonistic effect of tetrahydroproberberine (THP) homologues on alpha 1-adrenoceptor was studied by combination of radioligand binding assays and measurements of vasoconstriction responses. The results showed that l-tetrahydropalmatine (l-THP), l-stepholidine (l-SPD), THPB-18 and tetrahydroberberine (THB) competitively inhibited the 125I-BE2254 specific binding in rat cerebral cortex with pK1 values of 5.54 +/- 0.36, 5.56 +/- 0.47, 5.75 +/- 0.56 and 6.01 +/- 0.60, respectively, and the Hill efficiency was not significantly different from unity. They inhibited phenylephrine-induced constrictions with pA2 values of 5.48 +/- 0.58, 5.66 +/- 0.54, 5.64 +/- 0.34 and 5.45 +/- 0.76, respectively, and the slopes of Schild plot were not significantly different from unity. The results indicate that the 4 THP homologues are non-subtype selective competitive antagonists for alpha 1-adrenoceptor with similar affinities.
采用放射性配体结合试验与血管收缩反应测定相结合的方法，研究了四氢原小檗碱（THP）同系物对α1-肾上腺素能受体的拮抗作用。结果表明，左旋四氢巴马汀（l-THP）、左旋千金藤啶碱（l-SPD）、THPB-18和四氢小檗碱（THB）竞争性抑制大鼠大脑皮层中125I-BE2254的特异性结合，其pK1值分别为5.54±0.36、5.56±0.47、5.75±0.56和6.01±0.60，Hill系数与1无显著差异。它们抑制去氧肾上腺素诱导的血管收缩，pA2值分别为5.48±0.58、5.66±0.54、5.64±0.34和5.45±0.76，Schild图的斜率与1无显著差异。结果表明，这4种THP同系物是α1-肾上腺素能受体的非亚型选择性竞争性拮抗剂，亲和力相似。
