Experimental Study On Therapeutic Effects Of Whole Lung Lavage On Pneumoconiosis In Dogs

Objective To investigate the therapeutic effects of whole lung lavage on pneumoconiosis in dogs.Methods (1) Twelve mongrel dogs were randomized into 2 groups: control group and pneumoconiosis group. The dogs in control group were infused by sterile saline into the lungs,the pneumoconiosis group were infused by dust suspension into lungs at 1,20 day, then received whole lung lavage at 60 day and collect the lavaging liquids. (2) After quantity the lavaging liquids, which were divided into three experiments:①Centrifugating a fixed quantity lavaging liquids and stoving the sediments to constant weight, and then comparing the ratio of cleared matirals dry weight and sample liquids between the control group and the pneumoconiosis group. The dust content was obtained by ashing the cleared matirals to constant weight at high temperature, then comparing the ratio of dust content and sample liquids between two groups.②Counting total cellular score and classify fixed quantity lavaging liquids.③Alveolar macrophages were collected respectively from the lavaging liquids of two groups and cultured in the same cell density , 18h later, the levels of TGF-β1 protein in culture supernatant were measured by ELISA, Western Blot and RT-PCR were used to detect the protein and mRNA levels of MMP2 and MMP9 respectively after alveolar macrophages were cultured for 24h.Results (1) The ratio of cleared matirals dry weight and sample liquids in pneumoconiosis group was higher apparently than that of in control group(p<0.01), the ratio of dust content and sample liquids in in pneumoconiosis group was higher apparently than that of in control group too(p <0.01). (2) In lavaging liquids , total cellular score in control group was lower apparently than that in pneumoconiosis group (p<0.01), AM in pneumoconiosis group was higher than that in control group(p<0.05), but there were no difference between the two groups in the proportion of lymphocyte and neutrophil(p>0.05). (3) In culture supernatant, TGF-β1 protein increased in pneumoconiosis group. The protein and mRNA levels of MMP2 and MMP9 in pneumoconiosis group were higher than that in control group(p <0.01).Conclusions (1) Whole lung lavage can do much better to the prevention and cure of pneumoconiosis by clearing the dust in lungs. (2) Whole lung lavage can wash out lots of inflammatory cells , which prevent and postpone the progression of pneumoconiosis. (3) Inflammatory factors in AM can be cleared effectively, which also shows the effectivity of the treatment of whole lung lavage on pneumoconiosis.