Comparison of classical heat stroke between conscious and unconscious rat models

Objective　To reproduce conscious and unconscious classical heat stroke(CHS) models in conscious and unconscious rats, and the difference in heat stress response between the two models was investigated. Methods　Thirty-two male SD rats were randomly and equally divided into conscious classic heatstroke(C-CHS), unconscious classi cheatstroke(N-CHS), conscious normal control(C-NC) and unconscious normal control(N-NC)groups.Rats of C-CHS and N-CHS groups were put into artificial climate chamber, and exposed to 39℃ heat stress.Core temperature and systolic blood pressure(SBP) of rats were monitored via rectal thermal couple and by both invasive and non-invasive arterial blood pressure monitor instrument respectively. Heat stress responses of C-CHS and N-CHS rats were quantitatively analyzed and compared, and the survival time was also compared by K-M survival analysis. Results　There was a significant difference in regulatory features of the core temperature and SBP betweenC-CHS and N-CHS rats. Although no difference in maximum core temperature has been observed between N-CHS and C-CHS rats, but in comparison with C-CHS rats,N-CHS rats had significantly faster rise in core temperature(P<0.05), shorter heat stress time period,lighter total thermal load and severe thermal load(P<0.05).N-CHS rats had a poorer prognosis than C-CHS rats(P<0.05). Conclusion　In comparison with traditional heatstroke in unconscious rats, heatstroke in conscious rats model is more suitable for the investigation of experimental heatstroke, and further investigation of this model may help understand the mechanism ofpathogenesis of classic heatstroke.