The Preliminary Study Of The Injury Of Cardiac Muscle Following Combined Powder Explosive And Burn Injury In Rats

Objective: To investigate the injury of cardiac muscle in rats following combined powder explosive and burn injury and its possible pathogenesis. Methods: 128 Wistar rats were randomly divided into four groups which were normal control group (n=8), burn group (n=40), powder explosive group (n=40), combined powder explosive and burn group (n=40). The latter three groups were more divided into 1, 3, 6, 12, 24 hour post injury group, and in each sub group, the animal number is 8. The latter three groups were subjected to 20% total body surface area full thickness burn injury, powder explosive injury and combined powder explosive and burn injury respectively. The following of each group were examined and studied: the CK -MR activities of the blood plasma ,the water contents of the cardiac muscle, the MDA,RT,NO, TNF- a contents and MPO activities in myocardium; the histological and ultrastructural cardiac pathology changes, and correlation analysis were made between each of the two factors.Results: Compared with burn group and powder explosive group, the combined powder explosive and burn group's CK -MB activities of the blood plasma ,the water contents of the cardiac muscle, ET,NO,MDA, TNF- a contents and MPO activities in the heart, were all elevated significantly, and the histological and ultrastructural cardiac pathology changes were more severe. As to the above several factors, there was no essential difference between burn group and powder explosive group, the relationship between each of the two factors in CK -MB ,ET/NO,MDA, MPO, TNF- a was significance.Conclusions: 1 .The rat's myocardial injury was obvious after burn, powder explosive, combined powder explosive and burn injury. The degree of combined wound was more severe than the above two single wound. 2.There was myocardiac injury after combined burn and powder explosive injury, It could cause the deficiency of the oxygen and blood supply of the cardiac muscle, the confusion of the energy metabolism, the infiltration of neutrophil in cardiac muscle, the confusion of the oxygen-derived free radicals, the abnormal increase of the inflammation medium(TNF- a ).3.The increase of the ET, NO, MPO, MDA, TNF?a were more obvious after the combined powder explosive and burn injury than single injury.4. As to the above several factors, there was no essential difference between burn group and powder explosive group.