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Is a bipyridyl herbicide paraquat (paraquat, PQ), oral poisoning is the main way of poisoning, the high mortality rate of PQ poisoning. The PQ poisoning mechanism is not yet completely clear, multi-PQ absorption, produce a lot of oxygen free radicals cause lipid peroxidation of cell membranes of tissues and organs, resulting in multi-organ dysfunction, which is the most common and serious lung injury, often leading to pulmonary edema and pulmonary fibrosis. And currently there is no effective detoxification treatment. Of pesticide production and use of a large country, and achieved remarkable results with the national Ministry of Health, \herbicide paraquat, the highly toxic to humans and animals, the high mortality rate of acute poisoning, has become the focus of experiments explore and clinical. The experiment mainly through mechanical - biological methods to study human embryonic lung fibroblast proliferation, viscoelasticity and CTGF expression, interpretation of paraquat on the mechanism of lung cells, further explained the mechanism of lung injury or lung fibrosis mechanism, to further explore effective treatment means, to provide theoretical guidance. Experimental Methods: This study used human embryonic lung fibroblast MRC-5 was purchased from the cell bank of Chinese Academy of Sciences. Cultured in MEM medium (containing 10% fetal calf serum), at constant temperature and humidity, CO2 incubator culture CO2 content of 5%, temperature 37 ℃, and subcultured. MEM medium (containing 10% fetal calf serum) preparation of different paraquat concentration-50mg / L and 100mg / L and 200mg / L spare. Collection of MRC-5 cells were seeded in six-well culture plate, and subject to change after the cell growth of adherent cell culture medium containing paraquat, at constant temperature and humidity of the CO2 incubator culture CO2 content of 5%, temperature 37 ° C, 12h. 12h after the change to the cell culture medium free of paraquat to continue to foster. Cell culture medium (1) MRC-5 cells after paraquat treatment for non-paraquat cultured for 24h, the cells were treated with 0.25% trypsin digestion 5min after the preparation of single-cell suspensions research paraquat human lung fiber cell proliferation. (2) after paraquat treatment of MRC-5 cells for cell culture medium free of paraquat to continue training at 12h, 24h, 36h, 48h, 60h, 72h the cells were collected supernatant after centrifugation to remove impurities -70 ℃ refrigeration spare. Double-antibody sandwich ELISA detection of human lung fibroblast CTGF expression, to study the effects of paraquat on human lung fibroblast CTGF expression. Cell culture medium (3) The change does not contain paraquat paraquat treatment of MRC-5 cells, cultured for 24h, the cells were collected, made from the cell suspension by micropipette aspiration technique to detect lung fibroblasts viscoelastic to study paraquat impact on human lung fibroblasts biomechanical properties. Results: (1) normal cell proliferation activity of the MRC-5 cell proliferation activity significantly decreased, while after paraquat treatment, paraquat and the culture medium the greater the concentration, the lower the cell proliferation activity. (2) normal MRC-5 cells secrete a small amount of CTGF of CTGF concentration changes over time in the 0-48h increased significantly (P lt; 0.05), 60h and 72h CTGF concentration 48h no significant difference (P gt; 0.05) ; 50mg / L paraquat treatment ,0-36h CTGF concentration of a small amount of expression, no significant differences 48h CTGF expression was significantly increased (P lt; 0.05) ,48-72 hours of CTGF concentration varies with time significantly increased (P lt; 0.05), in 72 hours CTGF concentration increased significantly; 100mg / L ,0-36h CTGF concentration paraquat treatment has a small amount of expression, no significant differences (P gt; 0.05), 48h CTGF expression was significantly increased (P lt; 0.05) ,48-72h CTGF concentration changes over time and significantly increased (P lt; 0.05), CTGF concentration increased significantly in 72 hours; 200mg / L ,0-48h CTGF concentrations of paraquat treatment a small amount of expression, no significant differences (P gt; 0.05) 60h CTGF expression was significantly increased (P lt; 0.05), CTGF concentration at 72 hours significantly improved (P lt; 0.05). (3) MRC-5 cells after paraquat treatment viscoelastic parameters were significantly less than the normal MRC-5 cells (P LT; 0.05) means that the biomechanical properties of the MRC-5 cells after paraquat treatment reduces , it becomes more \After 100mg / L and 200mg / L paraquat treatment the viscoelasticity of the MRC-5 cells to less than 50mg / L paraquat treatment (P LT; 0.05), and 100mg / L and 200mg / L, paraquat treatment group viscoelasticity of the cell was no significant difference (P gt; 0.05). Conclusion: (1) after the paraquat treatment, a short time due to the toxic effects, lung fibroblast proliferation activity decreased. (2) lung fibroblasts treated for 72 hours in paraquat, CTGF expression and secretion of a substantial increase, will facilitate the process of pulmonary fibrosis. (3) the lung fibroblasts viscoelastic paraquat treatment decreased, indicating that the poisoning process, cytoskeletal changes. Change the growth and metabolism of normal lung fibroblasts and skeleton structure (4) of paraquat poisoning, suggesting that early in poisoning by inhibiting CTGF overexpression repair cell's internal skeleton structure for treatment.
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