目的：研究石膏及白虎汤对发热模型大鼠的清热作用以及对大鼠血清Na/Ca比值的影响。方法：大鼠背皮下注射干酵母混悬液复制致热模型，观察石膏及白虎汤的清热作用；取造模前、后和给药后3个时间点的大鼠血清，微波消解，ICP-OES测定血清中Na、Ca含量，分析Na/Ca比值的变化。结果：石膏及白虎汤对干酵母致热模型大鼠均有清热作用，白虎汤效果显著；白虎汤组发热模型大鼠血清中Na/Ca比值明显降低。结论：石膏及白虎汤清热作用机理可能与降低体内Na/Ca比值有关。

This work studied the effect of gypsum and Baihu Decoction on reducing fever and on the Na/Ca ratio in sera of febrile rats induced by dried yeast. The rat pyrexia models were established by injecting dry yeast hypodermically. Sera were collected at three different time points. The content of Na and Ca was determined by ICP-OES, and the ratio of Na/Ca was calculated. Gypsum and Baihu Decoction significantly reduced fever of febrile rats induced by dried yeast, and the Na/Ca ratio of the Baihu Decoction group went down after intragastric administration. The result showed that the functioning mechanism of gypsum and Baihu Decoction to reduce fever may be associated with reduction of the Na/Ca ratio.

科学技术部“十一五”国家科技支撑计划子课题（2006BAI09B06-04）：中药饮片炮制技术和相关设备研究——煅制技术及相关设备的研究，负责人：蔡宝昌；江苏省中药炮制重点实验室开放式课题（ZYPZ005）：国家药典含钙矿物中药炮制前后指纹图谱的研究及其血清化学指纹图谱的探讨，负责人：李祥。