The Study Of The Effect Of Intrapulmonary Lymphatic Transport In The Pathogenesis Of Silicosis

Objectives To explore the role of lymphatic transportation on the pathogenesis of silicosis by observing the intrapulmonary lymphangiogenesis in silicotic rats combine with the effects on the process of silicosis by promoting or blocking lymph circulation.Methods SD rats(n=84)were randomly divided into normal control group,lymphatic blocking control group,silica exposure group,lymphatic promoting and lymphatic blocking group,the latter three groups were further divided into four subgroups from 1,2,4 to 8w,six rats in each subgroup.The rats in silica exposure group were constructed by using the HOPE-MED8050 control device in the silica exposure group,and the time for exposing to silica is 3h every day.The rats in lymphatic promoting group were treated with sulfotanshinone sodium injection by intraperitoneal injection(15mg/kg/d)after expose to silica everyday;The rats in lymphatic blocking group were treated with the electrocoagulator to solidify the thoracic duct and expose to silica in the same condition.The rats in the lymphatic blocking control group were treated with the same method but not expose to silica.Normal control group was not treated.Lymphatic fluid,serum and lung tissue of rats were collected,the maximum transverse diameter of right lower lobe was taken,paraffin embedding slices,the pathological changes and collagen expression in lungs were observed by HE and Masson staining;Immunohistochemistry was used to observe the proliferation of lymphatic vessels in the lungs.The contents of MDA and TAOC in lymphatic fluid were detected by commercial kits.Western blot was used to detect the expression of MCP-1 and COX-2 in lung tissues.The content of HA and LN in serum of rats was detected by ELISA.Results 1 HE and Masson staining proved that the model of the experimental silicotic rats was successfully constructed,and the lymphatic blocking group was more serious than that of the silica exposure group,while the degree of lesion of the lymphatic promoting group was reduced.2 Silica exposure and lymphatic promoting group appeared lymphangiogenesis at the beginning of the exposion,and the lymphatic promoting group were more obvious,but the lymphangiogenesis in lymphatic blocking group were later.3 The content of MCP-1 in silica exposure group,lymphatic promoting and lymphatic blocking group were all rised from 1W to 8W(P<0.05).However,except for the 1W subgroup,the content of MCP-1 in lymphatic promoting group was lower than that of the silica exposure group.In addition to the 8W subgroup,the content of MCP-1 in lymphatic blocking group was higher than that of the silica exposure group(P<0.05).4 The content of COX-2 in lung of silica exposure group,lymphatic promoting and lymphatic blocking group were all rised from 1W and then decreased(P<0.05).The content of COX-2 in lymphatic promoting group was lower than that of the silica exposure group,the content of COX-2 in lymphatic blocking group was higher than that of the silica exposure group(P<0.05).5 The content of T-AOC in lymph of silica exposure group,lymphatic promoting and lymphatic blocking group were all decreased from 1W and then rised(P<0.05).The content of T-AOC in lymphatic promoting group was higher than that of the silica exposure group,the content of T-AOC in lymphatic blocking group was lower than that of the silica exposure group(P<0.05).6 The content of MDA in lymph of silica exposure group,lymphatic promoting and lymphatic blocking group were all rised from 1W and then decreased(P<0.05).The content of MDA in lymphatic promoting group was lower than that of the silica exposure group,in addition to the 4W subgroup,the content of MDA in lymphatic blocking group was higher than that of the silica exposure group(P<0.05).7 The content of LN in serum of silica exposure group,lymphatic promoting and lymphatic blocking group were all rised from 1W and then decreased(P<0.05),The content of LN in lymphatic promoting group was lower than that of the silica exposure group,in addition to the 8W subgroup,the content of LN in lymphatic blocking group was higher than that of the silica exposure group(P<0.05).8 The content of HA in serum of silica exposure group,lymphatic promoting and lymphatic blocking group were all rised from 1W and then decreased(P<0.05).The content of HA in lymphatic promoting group was lower than that of the silica exposure group,the content of HA in lymphatic blocking group of 1W and 4W subgroups was higher than that of the silica exposure group(P<0.05).Conclusions 1 In the early stage of silicosis,intrapulmonary lymphatic hyperplasia was presented,indicating that intrapulmonary lymphatic transport was involved in the pathogenesis of silicosis.2 Pulmonary lymphatic transport plays an important role in the pathogenesis of silicotic rats,suggesting that improving the lymphatic circulation may be an effective way to alleviate the development of silicosis.