Study On Distribution Of CTGF And FGF-2 In Lungs Of Different Age Yak

Objects: This study was aimed to investigate the res Ponse mechanism of yak lung ada Pting altitude hy Poxia.In order to research the relationshi P between lung tissue structure and the tolerance to hy Poxia,we studied the ex Pressions and effects of CTGF and FGF-2 in the yak lung,the factors which have s Pecific effects on connective tissue and smooth muscle hy Per Plasia.The study was to investigate the role of these factors in the formation of hy Poxic ada Ptive structure in yak's lungs.Methods: Collagen fibers were examined in newborn,half-year and adult yak lungs by EVG staining.Immunohistochemical technique was used to investigate the accurate distribution and expression of CTGF and FGF-2 in three age groups.Results: ? In three age groups,collagen fibers which mainly surrounded the branches of the bronchus and the pulmonary arteries.?CTGF were mainly located in the epithelial cells of bronchus branches,the expression level of the highest is half-year group(P<0.05),newborn by the second,adult last,and there was no significant difference between the newborn and adult(P>0.05).CTGF were examined fewer in the pulmonary vascular endothelium.In the pulmonary arteries,the expression level of CTGF in the three age groups decreased slowly(P> 0.05).In the arteries(100um?200um),the expression level of the highest is half-year group(P<0.05),adult by the second,newborn last(P>0.05).In the arteries(>200um),the highest is half-year group,adult by the second,newborn last(P>0.05).?FGF-2 is mainly located in the smooth muscle cells and epithelial cells of the bronchial branches and pulmonary arteries.In the bronchial,half-year group was the highest(P<0.05),newborn by the second(P<0.05),adult last(P<0.05).The expression level of bronchioles was the highest in the half-year group(P>0.05).FGF-2 level in the microvascular(50um)was the highest in the half-year group,newborn followed,adult last(P<0.05).The expression level in the three groups of pulmonary arteries(100um?200um)increased slowly(P>0.05).The ex Pression of pulmonary arteries(> 200um)was the highest in the half-year group,and newborn was the lowest(P<0.05).Conclusion: ?In newborn,3-5 months old and adult yak,collagens were distributed in the bronchial branches and pulmonary arteries.Collagen deposition in the vessel wall was to further promote thickening vascular myometrium adapting to the hypoxic environment.?Compared with the newborn and adult groups,the half-year CTGF distribution of bronchial branches and pulmonary arteries(>100um)was the highest,and it is especially obvious for the diameter greater than 100 um.It indicated that the growth of large arteries in yak was faster and effects of hypoxia on CTGF for the formation of pulmonary blood vessels of yak.?FGF-2 plays a stable and sustained role in both bronchial and pulmonary arteries of yak,suggesting that FGF-2 may affect the formation of hypoxic special structures of myometrial and pulmonary vessels in yak lungs.