石膏剂量变化对麻杏石甘汤解热效应的量效关系研究

目的: 探讨麻杏石甘汤中石膏剂量与解热作用的量效关系。 方法: 以麻杏石甘汤原方用量为基础，维持方中麻黄、苦杏仁和炙甘草药量不变，仅改变方中石膏用量，另设麻杏石甘汤去石膏方。采用尾静脉注射脂多糖（LPS）造模，造模后每0.5 h记录1次体温，统计结果并计算出体温反应指数（TRI）;测定造模后6.0 h血浆前列腺素E₂（PGE₂）含量。 结果: 石膏用量变化的麻杏石甘汤及其去石膏方均能够降低LPS致热大鼠体温，同时降低血浆PGE₂水平。与无石膏方比较，石膏加入方中后，各组在降低大鼠体温、降低血浆PGE₂水平方面均有显著性意义（P<0.05，P<0.01）。半数有效量EC₅₀ 2.785 g·kg^-1;治疗窗为D]₂₀~ D]₈₀ 2.218~3.497 g·kg^-1;阈剂量 2.218 g·kg^-1。 结论: 麻杏石甘汤去石膏方具有弱的解热作用可能与汤剂中含有的甘草甜素、苦杏仁苷及麻黄的作用有关。当石膏加入方中，解热效应迅速增强，并在一定的剂量范围内达到最大效应，即使再增大石膏用量，解热效应持续维持在最大效应。

Research of Dose-effect Relationship of Maxin Shigan Decoction with the Dosage Changes of Gypsum Fibrosurn

Objective: To explore the dose-effect relationship of Maxin Shigan decoction with dosage changes of Gypsum Fibrosum. Method: Based on the original dose of Maxing Shigan decoction,the dose of Ephedrae Herba, Armeniacae Semen Amarum and Glycyrrhizae Radix et Rhizoma Praeparata cum Melle was unchanged,dosage of gypsum was changed,in another Maxing Shigan decoction there was no Gypsum. The male Sprague-Dawley rats were randomly divided in to 13 groups,including Maxing Shigan decoction dose 1-dose 10,positive drug group,normal group and model group. Fever model was induced by injecting lippolysaccharide (LPS) through the tail vein.The temperatures was recorded,and TRI was calculate;concentration of prostaglandin E₂(PGE₂) in the plasma was detected;Graphpad prism 5.0 software was used to dose-effect analysis. Result: Both the Maxing Shigan decoction with change of dosage of Gypsum Fibrosum and the decoction with no Gypsum could reduce body temperature in fever rats,and reduce the plasma PGE₂ levels. Compared to the decoction without Gypsum Fibrosum,the groups with Gypsum Fibrosum significantly decrease body temperature,PGE₂ levels and temperature reaction index(P<0.05,P<0.01). Concentration for 50% of maximum effect(EC₅₀) was 2.785 g· kg^-1;Therapeutic window for D]₂₀-D]₈₀ was 2.218 to 3.497 g· kg^-1. Conclusion: Decoction without Gypsum Fibrosum has weak antipyretic effect,which may be related to the effect of Glycyrrhizin,Amygdalin and Ephedrae Herba. Decoction with Gypsum Fibrasum enhanced rapidly antipyretic effect,and with a small dosage range the effect showed a obvious change.