Development of a chronic stress-induced low-grade fever animal model and its mechanisms

为了更好地了解在心理社会应激情况下发生的持续性低烧患者，我们旨在建立应激诱导的慢性低烧（热疗）动物模型。我们测量了雄性Wistar大鼠在经历4个社会失败期后的核心体温（Tc）（每个阶段包括在光照周期中每天7次1小时的应激暴露，然后是无应激日）。在4个社会失败期后，应激大鼠在光照期和黑暗期的Tc值均较对照大鼠明显升高（+0.2 ~ 0.3℃）。他们也表现出类似抑郁的行为。在最后一次社交失败结束8天后，仍观察到高热和抑郁样行为。这些结果表明，反复的社会失败压力会引起大鼠的慢性高热，这与抑郁症的行为有关。

To obtain a better understanding of patients with persistent low-grade fever that develops in psychosocially stressful situations, we aimed to develop a stress-induced chronic low-grade fever (hyperthermia) animal model. We measured core body temperature (Tc) in male Wistar rats after they were subjected to 4 social defeat periods (each period consisting of 7 daily 1 h stress exposures during the light cycle followed by a stress-free day). After 4 periods of social defeat, stressed rats showed a small but significantly higher (+0.2-0.3℃) Tc versus control rats during both light and dark periods. They also showed depression-like behavior. Hyperthermia and depression-like behavior were still observed 8 days after cessation of the final social defeat session. These results suggest that repeated social defeat stress induces a chronic hyperthermia in rats that is associated with behavior resembling depression.