title: Alteration of elastin, collagen and their cross-links in abdominal aortic aneurysms.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Vascular Surgery, S. Carlo Borromeo Hospital, University of Milan, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Carmo
authors.forename: L
authors.initials: L
authors.lastname: Colombo
authors.forename: A
authors.initials: A
authors.lastname: Bruno
authors.forename: F R M
authors.initials: FR
authors.lastname: Corsi
authors.forename: L
authors.initials: L
authors.lastname: Roncoroni
authors.forename: M S
authors.initials: MS
authors.lastname: Cuttin
authors.forename: F
authors.initials: F
authors.lastname: Radice
authors.forename: E
authors.initials: E
authors.lastname: Mussini
authors.forename: P G
authors.initials: PG
authors.lastname: Settembrini
mesh_terms: D000368:Aged; D001012:Aorta, Abdominal / Q000737:chemistry; D017544:Aortic Aneurysm, Abdominal / Q000378:metabolism* / Q000503:physiopathology; D002851:Chromatography, High Pressure Liquid; D003094:Collagen / Q000032:analysis / Q000378:metabolism*; D004549:Elastin / Q000032:analysis / Q000378:metabolism*; D005260:Female; D006801:Humans; D006901:Hydroxylysine / Q000032:analysis; D006909:Hydroxyproline / Q000032:analysis; D066298:In Vitro Techniques; D008297:Male; D011726:Pyridinium Compounds / Q000032:analysis
chemical_list: D011726:Pyridinium Compounds; D006901:Hydroxylysine; D003094:Collagen; D004549:Elastin; D006909:Hydroxyproline