基于“体热平衡”原理探讨芍药甘草汤“酸甘化阴”配伍抵御高温环境大鼠死亡的机理

High temperature operation damage is a practical problem that can not be avoided by people engaged in agriculture, military, architecture and many other industry groups.Created by Zhang Zhongjing,the Shaoyao Gancao Decoction is a representative formula to dissect “Suangan Huayin”theory.And the Symptoms of “Cramp Foot”,an ancient Chinese disease that can be cured by this formula,resemble those of the high-temperature-operation-caused “Heat cramps”.Previous studies showed Shaoyao Gancao Decoction can significantly resist death of rats in high temperature environment（36±1℃）, increase the activity of PGC1 α, CS, OGDH in rat skeletal muscle and increase the amount of sweating.So the research group hypothesises that mechanism of Shaoyao Gancao Decoction resists rats' death in high temperature environment is related to the regulation of body heat balance.By analyzing the influence of the decoction to the heat production receptor T3, T4, TSH,TRH, CS, OGDH, mitochondrion RCR and COX IV as well as radiating receptor Na+、K+、Ca2+、Mg2+、Ach、E/A、receptor M3 and β2 of both normal rats and Central nervous narcotic rats,we are abled to identify the relationship in how this formula resist high temperature and regulate body heat balance.Also,the theory of “Suangan Huayin” is clarified to provide experimental basis for the clinical application of treating “Cramp Foot”,the prevention or damage reduction of high temperature,the expansion of clinical use and the development of new drugs or health care products.

高温作业损害是当前从事农业、军事、建筑等众多行业群体不可回避的现实问题。芍药甘草汤是仲景酸甘化阴配伍的代表方剂，原方主治“脚挛急”的症候表现与高温作业之“热痉挛”病有诸多相似之处。课题前期研究发现：芍药甘草汤可显著抵御高温环境（36±1℃）大鼠死亡，提高大鼠骨骼肌PGC1α、CS、OGDH活性，增加大鼠出汗量，故课题组提出“芍药甘草汤抵御高温环境大鼠死亡机理与调控‘体热平衡’有关”的假说，拟通过分析该方对正常大鼠、中枢神经麻醉模型大鼠“产热”环节T3、T4、TSH、TRH、CS、OGDH、线粒体RCR、COXⅣ等及“散热”环节Na+、K+、Ca2+、Mg2+、Ach、E/A、M3受体、β2受体等的影响，明确该方抵御高温与调控“体热平衡”的关系，阐明其“酸甘化阴”配伍原理的内涵，为临床应用该方治疗“脚挛急”证、预防或降低高温对机体的损害、扩大其临床用途、开发抗高温保健品或新药奠定实验基础。

通过观察芍药甘草汤及其拆方对正常动物、中枢神经麻醉（以下简称“麻醉”）动物在不同高温环境下“体热平衡”相关指标的影响,揭示其抵御高温环境大鼠死亡的机理。结果表明：1）中等高温环境可显著降低正常和麻醉大鼠体重、摄食量,抑制正常大鼠血清K+离子浓度、肝组织CS、OGDH含量、腹主动脉β2受体表达,而显著增加正常大鼠和麻醉大鼠出汗量,提升正常大鼠血清TG和腓肠肌OGDH水平及大鼠线粒体数量；2）对中等高温正常大鼠,芍药甘草汤可降低腓肠肌OGDH含量,单味白芍则可降低血清ACH含量、提高腓肠肌CS水平,单味甘草则可提升FBG水平、降低血清TSH、ACH水平；对中等高温麻醉大鼠,芍药甘草汤可降低大鼠血清K+浓度、增加肝组织OGDH含量,单味白芍则可降低大鼠血清FBG、TC和ACH水平、增加腓肠肌OGDH含量,单味甘草可使大鼠血清Na+、TRH水平、肝组织CS及腓肠肌OGDH含量呈显著上升；3）对正常大鼠,高温环境可降低大鼠血清T3、T4、CRH水平,而增加血清TRH、PGE和心、肝组织HSP70含量,各给药组对T4水平的下降呈显著抑制作用,单味甘草组对CRH的下降呈协同作用；对麻醉大鼠,高温环境可降低血清T3水平,而增加血清TSH和心肌HSP70含量,单味白芍组协同降低心肌HSP70水平,而单味甘草组则显著提升血清PGE水平,且协同降低心肌HSP70水平；4）在超高温环境下,正常大鼠血清ACH、PGE、脑、肝组织HSP70水平、肝组织M3受体、心肌TRPV3蛋白表达均呈上升趋势,而下丘脑TRPV3、TRPV4蛋白表达、心、下丘脑TRPV4mRNA和下丘脑TRPV3mRNA表达则呈显著性下降,芍药甘草汤及其拆方对以上指标有一定的干预作用,其中芍药甘草汤可协同增加血清PGE水平、增加下丘脑TRPV3mRNA表达量,而抑制下丘脑HSP70水平、降低肝组织β2受体mRNA表达量；单味白芍亦可协同增加血清PGE水平、增加肝组织β2受体蛋白和心、下丘脑TRPV3、TRPV3mRNA表达,但降低下丘脑HSP70水平、肝PGC1α受体、心TRPV3、TRPV4蛋白表达量；单味甘草则可降低下丘脑、心HSP70水平和心TRPV4蛋白表达,增加肝M3受体mRNA表达。课题为方剂性味配伍的内涵研究提供了新思路,为开发抗高温新药提供可靠的数据支持。