Sex differences in the immune response can also affect the febrile response, particularly the fever induced by lipopolysaccharide (LPS). However, other pathogen-associated molecular patterns, such as zymosan A (Zym) and polyinosinic-polycytidylic acid (Poly I:C), also induce fever in male rats with a different time course of cytokine release and different mediators such as endothelin-1 (ET-1). This study investigated whether female sex hormones affect Zym- and Poly I:C-induced fever and the involvement of ET-1 in this response. The fever that was induced by Zym and Poly I:C was higher in ovariectomized (OVX) female rats compared with sham-operated female rats. Estrogen replacement in OVX females reduced Zym- and Poly I:C-induced fever. The ET_B receptor antagonist BQ788 reversed the LPS-induced fever in cycling females but not in OVX females. BQ788 did not alter the fever that was induced by Zym or Poly I:C in either cycling or OVX females. These findings suggest that the febrile response in cycling females is lower, independently of the stimulus that is inducing it and is probably controlled by estrogen. Also, ET-1 seems to participate in the febrile response that was induced by LPS in males and cycling females but not in the LPS-induced fever in OVX females. Additionally, ET-1 was not involved in the febrile response that was induced by Zym or Poly I:C in females.

免疫反应的性别差异也会影响发热反应，尤其是脂多糖 (LPS) 引起的发热。然而，其他病原体相关的分子模式，如酵母多糖 A (Zym) 和聚肌苷-多胞苷酸 (Poly I:C)，也会在具有不同细胞因子释放时间进程和不同介质（如内皮素-1）的雄性大鼠中引起发热(ET-1)。本研究调查了女性性激素是否会影响 Zym 和 Poly I:C 诱导的发热以及 ET-1 在该反应中的参与。与假手术的雌性大鼠相比，在切除卵巢 (OVX) 的雌性大鼠中，由 Zym 和 Poly I:C 引起的发热更高。OVX 雌性中的雌激素替代降低了 Zym 和 Poly I:C 引起的发热。ET _B受体拮抗剂 BQ788 在骑自行车的雌性中逆转了 LPS 诱导的发热，但在 OVX 雌性中没有逆转。BQ788 没有改变 Zym 或 Poly I:C 在骑自行车或 OVX 雌性中引起的发烧。这些发现表明，骑自行车的女性的发热反应较低，这与诱导发热的刺激无关，并且可能受雌激素控制。此外，ET-1 似乎参与了 LPS 在雄性和骑自行车的雌性中引起的发热反应，但不参与 LPS 引起的 OVX 雌性中的发热。此外，ET-1 不参与 Zym 或 Poly I:C 在女性中引起的发热反应。