Influence of Hepatectomy on Body Temperature Change in Rats

Abdominal surgery, especially liver resection and transplantation, increases body temperature during and after surgery, but the precise mechanism (s) underlying this effect are not well understood. The present study thus sought to investigate this phenomenon using an experimental rat model. Specific pathogen-free male Sprague-Dawley rats, 5 weeks of age, underwent a two-thirds partial hepatectomy (PH), one-third splenectomy, or left kidney resection, and then rectal temperature was measured for 5 consecutive days after surgery. Rectal temperature increased in PH rats to a peak on day 4, but no change in temperature was detected after splenectomy and kidney resection. In the second part of the study, we examined the influence of gadolinium chloride and interleukin-1β monoclonal antibody (IL-1β mAb) on the increase in rectal temperature following PH. Treatment of rats with 20mg/kg gadolinium chrolide or 200µg IL-1β mAb inhibited the PH-induced increase in rectal temperature and decrease in IL-1β and prostaglandin E2, which act as pyrogens to change the thermoregulatory set point in the hypothalamus. These results suggest that abdominal surgery, especially liver resection, caused an increase in endogenous pyrogen production that results in increased body temperature