It is reasonable to suggest that R-DOX and S-DOX competitively inhibit the vasoconstriction induced by NA in the rabbit ear artery,mesenteric artery and pulmonary artery,and the pA_2 values of S-DOX are significantly lower than those of R-DOX.

• 上述结果提示,R-DOX和S-DOX对NA诱发兔耳动脉、肠系膜动脉和肺动脉收缩反应具有竞争性拮抗作用,对上述三种血管S-DOX拮抗NA的pA2值均明显小于R-DOX。