Aim To determine antagonist strength and relative soloetivity of Lho raoomio TJ0711 ( R/S-TJ0711 ) and its optical isomers S- and R-TJ0711 on each adrenergic roooptor subtypo. Methods Experi-monts wore carried out in isolatod organs, and antago-nist parameter ( pA2 ) values of the test substanees were measured for β1 and β2 , α1 and α2 roooptor with right atria and traeheas of guinea pig, anoeoeeygeus muscles and vas deferens specimens of rat, respective-ly. Results The pA2 values of R/S-, S- and R-TJ0711 for p, receptor were 7. 35 , 7. 22 and 7. 17; for β2 roooptor were 6. 24, 6. 11 and 6. 23 ; for a, receptor were 7. 63 , 7. 37 and 7. 33 ; for α2 receptor were 5. 70,6. 08 and 5. 64, respectively. There was no sig-rnnificant difference between pA2 values of S- and R-TJ0711. Only for a, receptor, the pA, values of R/S-TJ0711 were significantly higher than those of S- and R-TJ0711. Conclusions The characteristics of S-and R-TJ0711 represented are consisent with each other in isolatod organs. To antagonize a, receptor, S-and R-TJ0711 may exhibit synergy , which makes their antago-nistic intensity significantly lower than the raoomio. The test substanees show high selectivity for a, and β, reeeptor.%目的 测定外消旋TJ0711(R/S-)及其两种旋光异构体(S-和R-)对肾上腺素受体各亚型拮抗作用的强度及相对选择性.方法 采用离体器官实验法,以离体豚鼠右心房、气管条、离体大鼠肛尾肌、输精管为标本分别测定受试物对β1和β2,α1和α2肾上腺素受体的拮抗参数(pA2).结果 R/S-、S-及R-TJ0711拮抗β1受体的pA2值分别为:7.35、7.22和7.17;拮抗β2受体的pA2值分别为:6.24、6.11和6.23;拮抗α1受体的pA2值分别为:7.63、7.37和7.33;拮抗α2受体的pA2值分别为:5.70、6.08和5.64.S-和R-TJ0711对4种肾上腺素受体亚型的pA2值差异无显著性.R/S-TJ0711拮抗α1受体的pA2值高于S-和R-TJ0711;对另外3种受体亚型,R/S-TJ0711与拆分体的pA2值差异无显著性.结论 在离体器官实验中,S-、R-TJ0711对肾上腺素受体各亚型的拮抗作用无明显差异,二者在拮抗α1受体时表现出协同作用;R/S-、S-和R-TJ0711对β1和α1受体的选择性较高.
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