Carmo M, Colombo L, Bruno A, Corsi F R M, Roncoroni L, Cuttin M S, Radice F, Mussini E, Settembrini P G
Department of Vascular Surgery, S. Carlo Borromeo Hospital, University of Milan, Italy.
Eur J Vasc Endovasc Surg. 2002 Jun;23(6):543-9. doi: 10.1053/ejvs.2002.1620.
although the mechanism of arterial dilation and aneurysm development has not been clarified, the degradation of elastin and collagen plays undoubtedly a critical role. We evaluated the elastin and collagen content through the detection of their cross-links in aneurysmal and non-aneurysmal abdominal aortic walls.
in 26 human abdominal aortic aneurysm specimens obtained during surgery and in 24 autopsy control samples of non-aneurysmal abdominal aorta the tissue content of elastin and collagen cross-links were measured by HPLC. Collagen was also detected by evaluating two characteristic amino acids, 4-hydroxyproline (4-hypro) with a colorimetric method and 5-hydroxylysine (5-hylys) by gas chromatography.
significantly fewer elastin cross-links were found in aneurysm samples compared to controls (desmosines and isodesmosines: 90% reduction; p<0.01). The opposite was true for pyridinoline collagen cross-links (350% increase) and deoxypyridinolines (100% increase, p=0.01). Tissue content of 5-hylys, 4-hypro and total amino acids were reduced significantly by 50% in aneurysmal samples.
beside confirming decreased elastin content in aneurysmal walls, these results show a concurrent increase of collagen cross-links. Since total collagen markers were decreased (decreased 4-hypro and 5-hylys) it is reasonable to suggest that in aneurysmal aortic walls old collagen accumulates cross-links while new collagen biosynthesis is somehow defective.
尽管动脉扩张和动脉瘤形成的机制尚未阐明，但弹性蛋白和胶原蛋白的降解无疑起着关键作用。我们通过检测动脉瘤性和非动脉瘤性腹主动脉壁中的交联来评估弹性蛋白和胶原蛋白的含量。
在手术中获取的26例人类腹主动脉瘤标本以及24例非动脉瘤性腹主动脉尸检对照样本中，采用高效液相色谱法测量弹性蛋白和胶原蛋白交联的组织含量。还通过比色法评估两种特征性氨基酸4-羟脯氨酸（4-hypro）以及气相色谱法评估5-羟赖氨酸（5-hylys）来检测胶原蛋白。
与对照组相比，动脉瘤样本中发现的弹性蛋白交联显著减少（锁链素和异锁链素：减少90%；p<0.01）。吡啶啉胶原蛋白交联（增加350%）和脱氧吡啶啉（增加100%，p=0.01）则相反。动脉瘤样本中5-hylys、4-hypro和总氨基酸的组织含量显著降低了50%。
除了证实动脉瘤壁中弹性蛋白含量降低外，这些结果还显示胶原蛋白交联同时增加。由于总胶原蛋白标志物减少（4-hypro和5-hylys降低），合理的推测是，在动脉瘤性主动脉壁中，旧胶原蛋白积累交联，而新胶原蛋白的生物合成存在某种缺陷。
