甘草酸单铵对内毒素诱发支气管高反应性的作用─β－cAMP向下调节影响

Effect of Ammonium Glycyrrhizanate agsinst endotoxininduced bronchial hyperrractivity-in relation to β-cAMP system

内毒素１ｍｇ／ｋｇｉｐｄ４豚鼠气道Ｈｉｓ引喘潜伏期明显缩短，Ｈｉｓ反应性增强，其ＰＤ２值增大，β受体功能降低，ＩＳＯ的ＰＤ２值下降，血浆中ｃＡＭＰ水平降低，甘草酸单铵（ＧＬ）５０ｍｇ／ｋｇｉｐ×４ｄ明显抑制ｉｐ内毒素后Ｈｉｓ反应性增高及β受体反应性降低，并显著提高血浆ｃＡＭＰ水平。提示ＧＬ对细菌感染诱发的支气管高反应性有预防作用，其作用机制与ＧＬ对β－ｃＡＭＰ系统向上调节有关。

days after endotoxin 1mg/kg intraperitoneal injection,the latent peroids of guinea pig inhaled histamine and PD2value of ISO and cAMP levels of plasma were decrease. meanwhile PD2 value of histamine decreased significantly.Ammonium Glycyrrhizanate50mg/kg ip×4inhibited the effect of endotoxin and incteased cAMP levels of plasma.The results indicated GL could prevent bscterial infection induced bronchial hyperreactivity. The mechanism may be inretation to that GL could be up regulation of β-cAMP system.