Mesh C L, Majors A, Mistele D, Graham L M, Ehrhart L A
Division of Vascular Surgery, Case Western Reserve University, Cleveland, OH, USA.
J Vasc Surg. 1995 Aug;22(2):142-9. doi: 10.1016/s0741-5214(95)70108-7.
Anastomotic intimal hyperplasia is characterized by smooth muscle cell (SMC) proliferation, but its final form is predominantly extracellular matrix. The purpose of this study was to compare collagen synthesis from graft SMC to that from adjacent native arterial SMC.
Thoracoabdominal bypass grafts were excised 20 weeks after implantation into canine models. SMC harvested from six anastomotic graft segments and adjacent native aorta were passaged twice, grown to near-confluence, and then assayed for collagen synthesis and total protein synthesis. In four of these sites type I alpha-1 procollagen mRNA levels were measured and normalized to glyceraldehyde-3-phosphate dehydrogenase. To control for increases in collagen synthesis associated with proliferation, SMC were plated at equal densities and tritium-thymidine incorporation and DNA concentration were determined. Data (mean +/- SE) were analyzed with two-factor ANOVA for repeated measures and paired Student t test and were considered significant if p < 0.05.
There was no difference in thymidine incorporation and total protein synthesis between groups, but collagen synthesis (graft: 52.9 +/- 1.6 disintegrations per minute/ng DNA versus native: 42.6 +/- 1.9 dpm/ng DNA; p = 0.03) and collagen synthesis as a percentage of total protein synthesis (graft: 7.16% +/- 0.11% versus native: 5.8% +/- 0.14%; p = 0.001) increased significantly in graft SMC as compared to native SMC. Type I alpha-1 procollagen mRNA levels were higher in graft SMC, but this difference was not significant.
Graft SMC specifically produce more collagen than SMC from adjacent native artery. This change does not simply reflect increases in either total protein synthesis or proliferation and may, in part, be due to increased collagen gene expression.
吻合口内膜增生的特征是平滑肌细胞（SMC）增殖，但其最终形式主要是细胞外基质。本研究的目的是比较移植血管SMC与相邻天然动脉SMC的胶原蛋白合成情况。
将胸腹部旁路移植血管植入犬模型20周后切除。从六个吻合口移植血管段和相邻的天然主动脉中获取的SMC传代两次，生长至接近汇合，然后检测胶原蛋白合成和总蛋白合成。在其中四个部位测量I型α-1前胶原mRNA水平，并以甘油醛-3-磷酸脱氢酶进行标准化。为控制与增殖相关的胶原蛋白合成增加，将SMC以相等密度接种，并测定氚胸腺嘧啶核苷掺入量和DNA浓度。数据（均值±标准误）采用双因素方差分析进行重复测量分析，并采用配对学生t检验，若p<0.05则认为具有显著性差异。
两组之间的胸腺嘧啶核苷掺入量和总蛋白合成无差异，但与天然SMC相比，移植血管SMC的胶原蛋白合成（移植血管：52.9±1.6每分钟衰变数/纳克DNA，天然：42.6±1.9 dpm/纳克DNA；p = 0.03）以及胶原蛋白合成占总蛋白合成的百分比（移植血管：7.16%±0.11%，天然：5.8%±0.14%；p = 0.001）显著增加。移植血管SMC中I型α-1前胶原mRNA水平较高，但差异不显著。
移植血管SMC比相邻天然动脉的SMC特异性地产生更多胶原蛋白。这种变化并非仅仅反映总蛋白合成或增殖的增加，部分可能是由于胶原蛋白基因表达增加所致。
