The effect of dexmedetomidine on myocardium injury in rats induced by thermal trauma

Objective To investigate the effect of dexmedetomidine on burn-induced myocardiac injury in severely burned rats.Methods Sixty Sprague-Dawley rats were divided into four groups(n=15),including sham group(Group S,underwent sham burn and normal saline of 1 mL/h were given),Burned group [Group C,third-degree burns over 30% total body surface area(TBSA) and normal saline of 1 mL/h for 6 h after burned were given],midazolam group [Group M,third-degree burns over 30% TBSA and midazolam of 0.6 mg/(kg·h) after burned were given],and dexmedetomidine group [Group D,third-degree burns over 30% TBSA and dexmedetomidine of 5 μg/(kg·h) after burned were given].Blood rheological parameters,and plasma tumor necrosis factor-alpha(TNF-α) and cTnI were assessed,while rat hearts was harvested for morphological examination 6 weeks after burned.Results Significant increase of ηb,Hct and cTnI were observed in Group C,M and D,when comparing with those in Group S(P0.05).However,significant reduction of ηb,Hct and cTnI were revealed in Group D and M,when comparing with those in Group C(P0.05).Furthermore,significantly more reduction in ηb and Hct were revealed in Group M than those in Group D(P0.05).Significant elevation of plasma MDA and TNF-α with compromised SOD activity were revealed in Group C,M and D,when comparing with those in Group S(P0.01).Meanwhile,significant reduction of TNF-α and cTnI with enhanced SOD activity were revealed in Group D when comparing with those in Group C(P0.01).Furthermore,significant reduction of MDA and TNF-α were revealed in Group D,when comparing with those in Group M(P0.05).Conclusion Dexmedetomidine effectively protects myocardium from burned-induced injury.