title: Analysis of elastin cross-linking and the connective tissue matrix of abdominal aortic aneurysms.
abstract: BACKGROUND
  Studies of the connective tissue matrix of abdominal aortic aneurysms (AAAs) have yielded conflicting results, and the glycosaminoglycan content has not been previously reported. The present work was done to evaluate the matrix components of AAAs, including the cross-link content of the residual elastin.
  
  
  METHODS
  Aortic specimens from AAAs and controls were sequentially extracted with salt, Brij, and urea; and the residual pellets were the subject of further studies. Elastin was purified by hot alkali treatment; other matrix components were determined by conventional methods.
  
  
  RESULTS
  Elastin content of the purified material was reduced in AAA. The cross-link content, desmosine+isodesmosine, was also reduced in AAA as a ratio to insoluble matrix dry weight. However, the cross-link content as a ratio to valine in the purified elastin was normal. The amino acid profiles of representative AAA and controls elastin preparations were similar to that of reference elastin. The amino acid content of the insoluble matrix of AAA revealed a significant reduction of protein (controls = 820 +/- 40 micrograms/mg versus AAA = 700 +/- 20 micrograms/mg, p < 0.05); the collagen content was unaltered. The content of glycosaminoglycan in AAA was noted to be significantly reduced (controls = 33.5 +/- 3.4 micrograms/mg versus AAA = 17.1 +/- 2.0 micrograms/mg, p < 0.05).
  
  
  CONCLUSIONS
  The data do not support the hypothesis of a primary cross-link deficiency in elastin of AAA; but the reduced contents of protein and glycosaminoglycans in AAA suggests basic biochemical alterations in the diseased aorta that warrant further investigation.
authors.affiliation: Department of Surgery, St. Luke's-Roosevelt Medical Center, Columbia University, New York, N.Y.
authors.forename: R H
authors.initials: RH
authors.lastname: Gandhi
authors.forename: E
authors.initials: E
authors.lastname: Irizarry
authors.forename: J O
authors.initials: JO
authors.lastname: Cantor
authors.forename: S
authors.initials: S
authors.lastname: Keller
authors.forename: G B
authors.initials: GB
authors.lastname: Nackman
authors.forename: V J
authors.initials: VJ
authors.lastname: Halpern
authors.forename: K M
authors.initials: KM
authors.lastname: Newman
authors.forename: M D
authors.initials: MD
authors.lastname: Tilson
mesh_terms: D000596:Amino Acids / Q000032:analysis; D017544:Aortic Aneurysm, Abdominal / Q000378:metabolism*; D003094:Collagen / Q000032:analysis; D003238:Connective Tissue / Q000737:chemistry*; D004549:Elastin / Q000032:analysis*; D006025:Glycosaminoglycans / Q000032:analysis; D006801:Humans
chemical_list: D000596:Amino Acids; D006025:Glycosaminoglycans; D003094:Collagen; D004549:Elastin