麻黄素衍生物对豚鼠心肌细胞内cAMP含量的影响

EPHEDRINE DERIVATIVES ON THE CONTENT OF INTRACELLULAR cAMP OF GUINEA-PIG VENTRICULAR MUSCLES

采用环磷酸腺苷（ｃＡＭＰ）蛋白质结合测定法，测定零浓度，最小浓度，半数有效量（ＥＤ５０）浓度和最大浓度的异丙肾上腺素，去甲伪麻黄素，普萘洛尔，甲基麻黄素对心肌细胞内ｃＡＭＰ含量的影响，结果看到随着异丙肾上腺素，去甲伪麻黄素浓度的增大，心肌细胞内ｃＡＭＰ的含量增加。以量－效曲线中求得的ＥＤ５０浓度对ｃＡＭＰ含量的影响最明显，去甲伪麻黄素对ｃＡＭＰ含量的影响是异丙肾上腺素的４７３％±０１８，随着普萘洛尔，甲基麻黄素浓度的增大，心肌细胞内ｃＡＭＰ含量逐渐减少，在最大浓度时达到最大抑制，甲基麻黄素对ｃＡＭＰ含量的影响是普萘洛尔的３８３％±０２。结果进一步证明，甲基麻黄素在一定浓度范围内具有β－受体阻滞剂的特性。

The changes of intracellular 35-cyclic adenosine monophosphate (cAMP) of ventricular muscles caused by isoprenaline(ISO);d-norpseudoephedrine (d-NPEP); propranolol(PROP) and l-methylephedrine (l-MEP) in concentrations of zero;minimum;ED50 and maximum used in document 1 were determined by a protein binding assay for cAMP.The results indicate that the content of intracellular cAMP of ventricular muscles increases in proportion to concentration of ISO and d-NPEP.The concentration of ED50 which got from cumulative concentration response curves affected content of cAMP significantly, d-NPEP affect content of intracellular cAMP is 473%±018 of that of ISO.The content of intracellular cAMP decreased in propotion as the concentration of PROP and l-MEP increased.The maximum concentrations caused the largest inhibition.The influence of l-MEP on cAMP is 383±02 of that of PROP.The results indicate further that l-MEP in certain concentrations has the character of beta-adrenoceptor blocking agent.