摘要
Background This study was designed to investigate changes in mRNA levels of transforming growth factor-β(TGF-β), collagen Ⅰ, and collagen Ⅲ in autogenous vein grafts. Methods Twenty-four New Zealand rabbits were randomly divided into 4 groups with 6 rabbits each. The external jugular veins of the New Zealand rabbits were harvested and grafted into the ipsilateral carotid artery. All rabbits were fed with a standard diet. After the operation, the rabbits were sacrificed at 1, 2, 3, or 4 weeks. TGF-β, collagen Ⅰ, and collagen Ⅲ mRNA levels in the venous grafts were measured by semiquantitative methods at every time point. The contralateral external jugular veins were also harvested and analyzed as controls. Glyceraldehyde-3-phosphate dehydrogenase was used as an internal standard to normalize all samples for potential variations in mRNA content. In order to observe the expression of TGF-β protein, immunohistochemical SABC methods were used. Results One week postoperation, the mRNA level of TGF-β was upregulated to 1.73±0.19 in the vein graft and 1.21±0.16 in the control vein (P<0.01). High mRNA levels were maintained until week 4 postoperation. The mRNA levels of collagen Ⅰ and collagen Ⅲ were also significantly increased to 2.18±0.21 versus 1.12±0.24 and 1.08±0.13 versus 0.83±0.12, respectively (P<0.05). Immunohistochemical staining revealed a higher density of TGF-β expression in the vein grafts.Conclusions An uninterrupted increase in mRNA levels of TGF-β, collagen Ⅰ, and collagen Ⅲ is observed in autogenous vein grafts. This increase may be the major cause of intimal hyperplasia, sclerosis, and even graft failure.
Background This study was designed to investigate changes in mRNA levels of transforming growth factor-β(TGF-β), collagen Ⅰ, and collagen Ⅲ in autogenous vein grafts. Methods Twenty-four New Zealand rabbits were randomly divided into 4 groups with 6 rabbits each. The external jugular veins of the New Zealand rabbits were harvested and grafted into the ipsilateral carotid artery. All rabbits were fed with a standard diet. After the operation, the rabbits were sacrificed at 1, 2, 3, or 4 weeks. TGF-β, collagen Ⅰ, and collagen Ⅲ mRNA levels in the venous grafts were measured by semiquantitative methods at every time point. The contralateral external jugular veins were also harvested and analyzed as controls. Glyceraldehyde-3-phosphate dehydrogenase was used as an internal standard to normalize all samples for potential variations in mRNA content. In order to observe the expression of TGF-β protein, immunohistochemical SABC methods were used. Results One week postoperation, the mRNA level of TGF-β was upregulated to 1.73±0.19 in the vein graft and 1.21±0.16 in the control vein (P<0.01). High mRNA levels were maintained until week 4 postoperation. The mRNA levels of collagen Ⅰ and collagen Ⅲ were also significantly increased to 2.18±0.21 versus 1.12±0.24 and 1.08±0.13 versus 0.83±0.12, respectively (P<0.05). Immunohistochemical staining revealed a higher density of TGF-β expression in the vein grafts.Conclusions An uninterrupted increase in mRNA levels of TGF-β, collagen Ⅰ, and collagen Ⅲ is observed in autogenous vein grafts. This increase may be the major cause of intimal hyperplasia, sclerosis, and even graft failure.
基金
ThisstudywassupportedbyagrantfromtheShanghaiPublicHealthBureau(NoBureau32)
