Different Changes Of Inflammatory Factors Expression And Prognosis In Burned Rats With Different Degrees Of Obesity

Objective:In order to clarify the changes of inflammatory factors and prognosis in burned rats with different degrees of obesity,this study intended to establish obesity and burn models through animal experiments,to investigate the effects of obesity on inflammatory factors such as MCP-1,IL-1β,TNF-α and growth factor VEGF in burned rats.And the risk of obesity on the prognosis of burns such as wound healing rate and skin growth was also analyzed,so as to provide basic research data for the interaction between obesity and burn.MethoMethods:1.After successful obesity modeling,according to the weight,SD rats divided into obese group,over-weight group and normal-weight group(60 rats in each group),and then each group was randomly divided into control group,Ⅱ°burn group and Ⅲ° burn group(20 rats in each subgroup).The burned area was 10cm2 on the rats’ back respectively.Body weight,fast blood glucose and the wound changes were measured on the 1st,3rd,7th and 14 th day after burn,and the blood and skin samples were also collected.2.Elisa test was used to detect the expression levels of inflammatory factors MCP-1,IL-1β,TNF-α and FINS in serum3.RT-PCR test was used to detect the relative expression of MCP-1,IL-1β,TNF-αand VEGF genes in wounds4.The wound healing rate and HE score were calculated to observe the skin growth condition.Results:1.Compared with the noResults:Compared with the normal control group,the Fast blood glucose(FBG),Fast insulin(FINS)and Insulin resistance index(IRI)were higher in the over-weight control group(P<0.05),and the FBG in the obese control group was higher than the normal group(P<0.05).On the first day after burn,FBG was higher in the normal group after Ⅲ°burn than in the control group(P<0.05).On the third day after burn,the FINS in the over-weight and Ⅱ° burn group was higher than that of the control group(P<0.05).On the 7th day after burn,the FINS and IRI of obesity and Ⅱ°burn group were higher than those of the control group(P<0.05).On the 14 th day after burn,the FINS and IRI in the normal group were higher than those of the control group(P<0.05).The FINS and IRI of the over-weight and Ⅲ°burn group were lower than the control group(P<0.05).Analysis of the interaction between burn and obesity found that,on the first day after burn,the FBG increased in normal and over-weight rats with Ⅲ°burn,and the FBG of the obese group decreased and was lower than normal and over-weight rats.On the 14 th day after the burn,the FINS and IRI of the normal group increased with the severity of burn.The FINS and IRI indexes of the normal group with Ⅲ° burn were higher than those of obesity and over-weight rats.The FINS and IRI indexes in over-weight group decreased after burn.The IRI decreased in the obese group of Ⅲ°burn,and the FINS increased,but lower than the normal group.2.Elisa test showed that in the non-burn(control group)group,The MCP-1,IL-1βand TNF-α protein expression in obesity and over-weight were higher than that in the normal group.The change of MCP-1,IL-1β and TNF-α protein expression in serum after burn were not significantly different.3.The RT-PCR test of wound tissue showed that the relative expressions of MCP-1,IL-1β and TNF-α genes in the obese group were higher than normal and over-weight group;and the expression of IL-1β and TNF-α genes in over-weight group were higher than normal group.And severe burns had a tendency to increase the expression of MCP-1,IL-1β and TNF-α genes in the obese group.On the 7th day after burn,the expression of VEGF in the normal burned group was higher than that in the over-weight and obese burned group.The relative expression of VEGF gene in the over-weight and normal group decreased after Ⅲ°burn.On the 14 th day after burn,severe burn had a tendency to decrease the expression of VEGF in obesity and normal group,and a tendency to increase in the over-weight group.4.In the obese group,the wound HE score was lower than that of normal and over-weight group on the 7th day after burn(P<0.05).The wound healing rate of the14 th day after burn injury was statistically significant(P=0.034),the wound healing rate of the normal group vs.over-weight group vs.fat group =(33.19±11.29)% vs.(34.77±14.76)%vs.(29.14±9.43)%.There was no statistically difference in HE score and wound healing rate between obesity,over-weight and normal group at other point in time after burn.5.On the 1st,3rd,7th and 14 th day after burn,the HE score and wound healing rate of Ⅲ° burn wounds were lower than that of Ⅱ° burns(P<0.05),and the regeneration status of Ⅱ° burn wounds was better than Ⅲ° burns ConclusioConclusion:1.The hyperglycemia,high insulin and insulin resistance responses in the normal group were stronger than those in the over-weight and obese group,suggesting that the over-weight and obese rats have certain adaptation and tolerance to high metabolic reactions in burns2.Burns and obesity have a mutually reinforcing effect on the body’s inflammatory response3.The degree of obesity does not affect the recent healing of wounds after burns,while obesity might have a potential effect on the long-term prognosis of wounds after burns.