目的 研究细菌内毒素不同给药方式对家兔致热的规律，计算出发热的阈值，为注射剂质量控制提供参考。方法 按照我国2010年版《中国药典》规定的热原检查方法，家兔采用不同给药方式注射5个不同剂量组的细菌内毒素，记录并绘制升温曲线图，通过曲线拟合计算出家兔体温升高0.6 ℃时发热的阈剂量。结果 家兔皮下注射细菌内毒素的发热阈剂量为45.24 EU·kg-1，最大升温时间位于3.0～4.5 h，升温维持时间位于0.5～4.0 h；肌内注射发热阈剂量为25.97 EU·kg-1，最大升温时间位于2.5～4.5 h，升温维持时间位于0.5～3.0 h；鞘内注射发热阈剂量为1.8 EU·kg-1，最大升温时间位于4.0～5.5 h，升温维持时间位于0.3～1.5 h。结论 细菌内毒素不同给药方式对家兔致热的规律有较大差别。

OBJECTIVE To study the pyrogenic pattern of endotoxin injected by different ways in rabbits， and to calculate the pyrogenic threshold dose， thus providing reference for better control on the quality of injections. METHODS Following the requirements of Pyrogen test in Chinese Pharmacopoeia 2010， the rabbits were injected five different doses of endotoxin through different delivery ways. Heating curves were drew， and analyzed. Through curve fitting the fever threshold doses were calculate. RESULTS The pyrogenic threshold dose of endotoxin in rabbits was 45.24 EU·kg-1 after subcutaneous injection. The maximum temperature rising appeared between 3 and 4.5 h after injection， and the fever lasted for 0.5-4.0 h. For intramuscular injection， the pyrogenic threshold dose was 25.97 EU·kg-1.The maximum temperature rising appeared between 2.5 and 4.5 h， and the fever lasted lasted for 0.5-3.0 h.For intramuscular injection. The pyrogenic threshold dose of endotorin was 1.8 EU·kg-1.The maximum temperature rising appeared between 4 and 5.5 h， and the fever lasted for 0.3-1.5 h. CONCLUSION The pyrogenic pattern of endotoxin in rabbits are quit different when injected through different ways.