The Research Of Formaldehyde On Lung Tissue's Oxidative Injury Of Mice

Objective:Formaldehyde is an original poison, has strongly stimulation or allergy, and can cause mostly whole-body's damage [1]. Formaldehyde also has reproductive poison and can cause cancer in animal's experiment[2-5]. Nowadays, the poison of formaldehyde becomes more and more serious with the wider use of it. So people concern effect of formaldehyde on health very much, and many specializes start to study formaldehyde more deeply and widely .In our study, we measure some of biological index in lung tissue paste and BALF, combing with pathology,to detect the effect of formaldehyde on lung tissue. At the same time observing the change of DNA of lung tissue in mice through carrying DNA from lung tissue, to detect the damage of formaldehyde on lung tissue more deeply.Method:Choose common KM mice of animal basement in JILIN university , weigh:15-17g, sex in half. Make into 3 dose groups and a control group ,12 animals each group ,sex in half. Using static inhalation style ,2 h everyday, 2 months continuously. Poisonous dose is 21 mg/m3,42 mg/m3 and 84 mg/m3 separately. Killing the animals in last inhaled formaldehyde, and take out the lung to detect.Weigh the lung after washing it with salt water and drying it on with filtrate paper, and ligate left part of the lung along bronchus. Wash right part of the lung with 0.9% salt water from bronchus for 5 times , collect the fluid . At the same time ,make the left part of lung into 3 parts: the upper lobe is solidified with 10% formaldehyde fluid; the middle lobe is weighed and frozen in -70oC to take DNA from lung tissue; the lower lobe is made serum with 0.9% salt water to measure biological index. All the statistic numbers can be counted by F and Q method.Take the fresh lung tissue along bronchus, and take it in 10% formaldehyde fluid to solidify after washing it with 0.9% salt water, dehydrated regularly and buried with paraffin wax, dyed with HE. In the end, observe it under the light microscopy.Take DNA from lung tissue with reagent box, and observe it after eletrophresis. Result:The activity of SOD in different dose groups were significantly lower than that of the control group, and the concentration of MDA were remarkably higher (p<0.01), but there is no difference among different dose groups (p>0.05). From pathology, we can see that it is manifestated as becoming bloodshots of pulmonary alveoli , expansion of pulmonary alveolus segment and inflammatory cells invasion under LM ,especially in higher group. LDH, ACP and AKP of different doses are all increased compared to control groups (p<0.05), but there is no difference among different dose groups (p>0.05).DNA of lung tissue in mice also changes from the picture we can see 1.There is lower DNA content in control and 21mg/m3 dose group. Although DNA can be checked, the belt of DNA is very dim without enough quantity. 2.DNA can be checked at the same position with samples of 42 and 84 mg/m3 dose group, but the belt of 42 mg/m3 dose group is very regular, from which we can conclude that there is only a kind of DNA. The belt of 84 mg/m3 dose group is wider than other belts, that is to say a part of DNA in sample starts to break apart and forms sections with lower molecular content. So we can see continuous DNA belt during electrophresis .Conclusion: From the experiment, we can conclude that formaldehyde can decrease anti-oxidative ability of mice and damage freebase or active oxygen clearing system , which can cause oxidative injury of lung tissue in mice. Through this study , we can better off explaining poisonous mechanics of formaldehyde and providing a scientific theory for preventing occupational diseases caused by formaldehyde.