The Experimental Research Of Hyperthermia Climate On Immune Function In Scalded Rats

Objective:To observe the change of T lymphocyte,NK cell and inflammatory mediators in the peripheral blood, and to investigate the change of hyperthermia climate on immune function in burned rats.Methods:72 healthy SD rats with 50% female and 50% male wighting 200±20g were randomly divided into four groups: group A (ordinary environment +burned + ordinary environment), group B (ordinary environment +burned + hot environment), group C (thermo-adaptive +burned +ordinary environment),group D(thermo-adaptive +burned + hot environment). Rats were bred in ordinary environment for a week, then group A and group B were continue to be bred in ordinary environment for ten days , group C and group D were put into artificial climate box ,exposed to Td (38±1)°C and RH (55±5)% for 1h each day, they had adapted the hot environment after nine days. in the eleventh day ,after depilated, anesthetized, the rats were burned on the back about 30%TBSAⅢdegree through pathological verificated. Then group A and group C were put into artificial climate box ,exposed to Td (21±1)°C and RH (55±5)%, group B and group D were put into artificial climate box ,exposed to Td (38±1)°C and RH (55±5)%. The wound of the rats were besmeared iodophor,2 times everyday. To observe the living conditions of rats in each group ,at 1,3,7 PBD, 6 rats of every group were also killed for sampling in the condition of asepsis to detect: the blood of inferior vena was taken and send to the room of Flow Cytometry in the sample tube with the anticoagulant EDTA to detect the amount of T lymphocyte,the activity of NK cell and CD25+T lymphocyte, the serum IL-6 level,the serum IL-10 and TNF-αwere measured with ELISA method.Results:1 the change of rectal temperate after and before heat stress: In the hot environment , the rectal temperate was obviously high after heat stress (P<0.01 or P<0.05),in the ninth day , the rectal temperate had restored to normal level. Compare with normal level ,there was no obvious difference (P>0.05)2 the living conditions of rats in each group: there was no death in group A,C and D. group B were put into hot environment to be bred, after 120min ,the rats started to be shortness of breath and dysphoria. To 4h , there was one rat to be death. to 1d, 15 rats had dead until 2d ,there was no one to be left.3 The comparison of immune function in burned rats(1) At 1 PBD,B group compared with A group, CD4 T lymphocyte,the ratio of CD4/CD8,CD25T lymphocyte and NK cell were significantly decreased (P< O.05 or P< O.O1),while CD8 T lymphocyte was increased obviously( P< O.O1).(2) C group compared with A group, CD8 T lymphocyte was increased obviously( P< O.O1)at 1 PBD, CD4 T lymphocyte was significantly decreased (P< O.05 ) at 7 PBD, the ratio of CD4/CD8,CD25T lymphocyte and NK cell were significantly decreased (P< O.05 or P< O.O1) at 1,7 PBD.(3)D group compared with C group, the amounts of CD3+ ,the ratio of CD4/CD8,CD25T lymphocyte were significantly decreased, CD8 T lymphocyte was increased obviously (P< O.05 or P< O.O1)at each time. CD4 T lymphocyte was significantly decreased (P< O.05 ) at 1 PBD, NK cell were significantly decreased (P< O.05 or P< O.O1) at 1,3 PBD.(4) D group compared with B group, the amounts of CD3 and CD4 T lymphocyte was significantly decreased (P< O.05 or P< O.O1) at1PBD,While CD4 T lymphocyte,the ratio of CD4/CD8,CD25T lymphocyte and NK cell were no significant diversity(P>0.05 ).4 The comparison of inflammatory mediators in burned rats(1) At 1 PBD,B group compared with A group, the serum IL-6 level,the serum IL-10 and TNF-αwere significantly higher( P< O.O1).(2) C group compared with A group, the serum IL-6 level,the serum IL-10 and TNF-αwere significantly higher( P< O.O1) at 1 PBD. while at 3,7 PBD , there were no significant diversity(P>0.05 ).(3) D group compared with C group, the serum IL-6 level,the serum IL-10 and TNF-αwere significantly higher( P< O.O1) at each time.(4) D group compared with B group, the serum IL-6 level,the serum IL-10 and TNF-αwere significantly lower( P< O.O1) at each time.Conclusions:1,Hyperthermia stress are serious impairment of cellular immunity in rats, expanding its inflammatory response.2,Heat acclimatization might be appropriate to impropriate cellular immune function in scalded rats under hyperthermia environment, enhanced capabilities to withstand hyperthermia.3,the compound damage of hyperthermia and burn was far stronger than burn itself on the body.