To investigate the differences between animal temperature controller (ATC) and artificial climate chamber (ACC) used for the establishment of classical heat stroke (CHS) rat model.

Twenty-four male specific pathogen-free Wistar rats were randomly (random number) and equally assigned to three groups, namely room temperature control (C-C) group, heat stroke under conscious state (HS-C) group, and heat stroke under anesthesia (HS-A) group. Rats of HS-C or HS-A group were placed into ACC or ATC, then exposed to 35 ℃ heat stress. The systolic blood pressure (SBP) and core body temperature (Tc) were monitored. The time required for onset of HS was recorded. The white blood cell count (WBC) in peripheral blood and serum levels of C-reactive protein (CRP) , tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) were measured. The histopathological changes of major organs were also confirmed by hematoxylin-eosin (HE) staining.

The onset time in HS-A group was significantly shorter than that in HS-C group [ (40.0±4.3) min vs. (110.1±5.3) min, P <0.011. The SBP and Tc at this moment were lower in HS-A group [ (159.1±5.91) mmHg vs. (174.54±5.77) mmHg, P<0.01; (43.5±0.4) ℃ vs. (44.4±0.2) ℃, P<0.01]. The WBC, CRP, TNF-α and IL-1β levels of these two HS groups were dramatically elevated compared with C-C group (P <0.01) . The inflammatory cytokines levels in HS-A group were significantly lower than those in HS-C group (P <0.01) , but there was no difference in WBC between them (P >0.05) . However, there was no obvious difference in histopathological change in major organ observed between HS-A and HS-C groups.

In comparison of these two methods, ATC is similar to ACC in respect of the establishment of CHS rat model. ATC is quicker in onset of HS, and more simplified and economical than ACC and could substitute ACC.

Heat stroke; Experiment animal model; Rat; Animal temperature controller; Artificial climate chamber