Disciplines Of Between Infection And Changes Of Rectal Temperature, Necrosis Of Gastrocnemius In Closed Tibial Fractures Model Of SD Rats

Background: Muscle necrosis sometimes occurs at the ends of fractures when patients suffer fracture and infection.Meanwhile,body temperature rises,and the realse of tumor necrosi factor-alpha (TNF-α), creatine kinase(CK),and lactate dehydrogenase (LDH) increase in the blood. Absorb heat and infectious fever are the main source of the rise in body temperature. TNF-αis proved to be one of pyrexins by papers,and it induces synthetic increase of prostaglandin E2(PGE2) which can make the rise of set point temperature in the anterior hypothalamus.CK and LDH are indirect indexs which can evaluate the level of muscle necrosis.But the diffference of body temperature between infectious fever and absorption heat and the correlation between necrosis of gastrocnemius and infection have not been reported by papers.By ways of making models of fracture and infection in Sprague-Dawley (SD) rats, the subject obtained rectal temperatures, biochemical criterias,and pathological sections.They can be used to provide the basis of evluating clinical fracture and infection with these datas.Objective: To obtain the diffference of rectal temperature between infectious fever and absorption heat , and to evaluate the relationship between infection and necrosis of gastrocnemius using TNF-α,CK,LDH,rectal temperature contrast to pathological changes of gastrocnemius on a closed tibial fracture in SD rat.Methods: Twenty-four healthy female Sprague-Dawley rats (weight (213.17±31.69) g,rectal temperatures(36.31±0.12)℃, room temperature (26-27)℃) were divided randomly into 4 groups on average: the group of no tibial fracture and no infection(A group),the group of unilateral tibial fractures and no infection(B group), the group of unilateral tibial fractures and infection in the ends of fracture(C group), the group of unilateral tibial fractures and both systemic infection and infection in the ends of fractures(D group).All rats were injected the same volume of bacteria liquid or normal saline in abdominal cavity according to body weight(4ml/kg) and the same limiting area (0. 1ml).The pathogen is staphylococcus aureus. Recording the difference value between rectal temperature of per hour and intial rectal temperature,and detecting indexs of CK,LDH,TNF-αusing serum of rat, and observing pathological sections of gastrocnemius six hours later.Results: After 6 hours of experiments,the raising values of rectal temperatures:A group (0.02±0.17)℃, B group (0.47±0.10)℃, C group (0.95±0.21)℃, D group(2.02±0.33)℃,all the adjacent groups P<0.05. Detcting indexs using serum of rat,the values of CK: A group (0.698±0.061) U/ml,B group(0.797±0.038) U/ml,C group(1.244±0.090) U/ml,D group (2.411±0.161) U/ml,all the adjacent groups P<0.05; The values of LDH:A group (4184.527±114.017)U/L,B group(5215.350±252.238) U/L,C group (6460.502±107. 819) U/L,D group (7930.190±380.951) U/L,all the adjacent groups P<0.05; The values of TNF-α: A group(0.030±0.052) U/ml, B group(5.151±1.987) U/ml,C group(19.459±9.059) U/ml,D group (98.527±6.300) U/ml,all the adjacent groups P<0.05. The pathological sections of gastrocnemius in the group injected staphylococcus aureus demonstrated more putrefactive than the group injected normal saline.Conclusions:1. Rectal temperatures of SD rats change in the closed tibial fractures model. Rectal temperatures raise after an hour and reach the highest values after six hours among the all six hours. Rectal temperatures of infectious groups and non-infectious groups have significant differences after six hours (P<0.05).The increase in rectal temperatures is positively correlates to seriousness of infection,and the raising values of rectal temperature: the group of no tibial fracture and no infection (A group)(0.02±0.17)℃,the group of unilateral tibial fractures and no infection (B group)(0.47±0.10)℃,the group of unilateral tibial fractures and infection in the ends of fracture (C group) (0.95±0.21)℃,the group of unilateral tibial fractures and both systemic infection and infection in the ends of fractures (D group)(2.02±0.33)℃.The change values of rectal temperature is positively correlated to the change values of TNF-α.2.SD rats of infectious groups and non-infectious groups have significant differences in CK,LDH and TNF-αin the closed tibial fractures model after six hours (P<0.05). The values of CK,LDH and TNF-αis positively correlated to seriousness of infection.Based on the analysis of pathological sections,the change values of CK and LDH is positively correlated to the changes in the necrosis of gastrocnemius.