title: [Pathologic change of elastic fibers with difference of microvessel density and expression of angiogenesis-related proteins in internal hemorrhoid tissues].
abstract: OBJECTIVE
  To investigate the pathological variations in internal hemorrhoid and evaluate the expression of nitric- oxide synthase(NOS),vascular endothelial growth factor(VEGF),matrix metalloproteinase- 2(MMP2) and MMP9.
  
  
  METHODS
  Normal anal cushion and internal hemorrhoids tissue samples were obtained from 24 patients with iii degree hemorrhoids after procedure for prolapse and hemorrhoids(PPH) procedure. The expression of NOS, VEGF, MMP2, MMP9 and CD34 were detected by immunohistochemical staining; the microvessel density (MVD) was counted by anti- CD34 antibody; the elastic fibers were detected by orcein staining.
  
  
  RESULTS
  There were statistically significant differences in the expression of MVD, VEGF, MMP9 between internal hemorrhoid tissue and normal anal cushions(P< 0.05). iNOS was significantly increased in hemorrhoid tissue, but no significant difference between normal anal cushions and hemorrhoid tissue. Morphological abnormalities such as breaking, distortion, mortality, hyaline degeneration were found in elastic fibers of internal hemorrhoid tissue, but not in normal anal cushions.
  
  
  CONCLUSIONS
  Angiogenesis is evident in hemorrhoid tissue, suggesting the possible mechanism in the pathogenesis of hemorrhoids. The direct degeneration effect of MMP9 on supporting structure elastic fibers in anal cushion is another important mechanism. The high expression of iNOS suggests the inflammatory factors involve in the pathogenesis of hemorrhoids, and NO may be involve in pathological effect on hemorrhoids.
authors.affiliation: Department of General Surgery, Beijing Chaoyang Hospital, Capital Medical University, Beijing 100020, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Han
authors.forename: Zhen-jun
authors.initials: ZJ
authors.lastname: Wang
authors.forename: Bo
authors.initials: B
authors.lastname: Zhao
authors.forename: Xin-qing
authors.initials: XQ
authors.lastname: Yang
authors.forename: Dong
authors.initials: D
authors.lastname: Wang
authors.forename: Jian-pin
authors.initials: JP
authors.lastname: Wang
authors.forename: Xiu-ying
authors.initials: XY
authors.lastname: Tang
authors.forename: Fa
authors.initials: F
authors.lastname: Zhao
authors.forename: Yan-ting
authors.initials: YT
authors.lastname: Hung
mesh_terms: D000328:Adult; D004547:Elastic Tissue / Q000378:metabolism / Q000473:pathology*; D006484:Hemorrhoids / Q000378:metabolism* / Q000473:pathology*; D006801:Humans; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D055806:Microvessels / Q000473:pathology; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000473:pathology; D019001:Nitric Oxide Synthase / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D042461:Vascular Endothelial Growth Factor A; D019001:Nitric Oxide Synthase; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9