[Pathologic change of elastic fibers with difference of microvessel density and expression of angiogenesis-related proteins in internal hemorrhoid tissues].
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.
Han
Wei
W
Department of General Surgery, Beijing Chaoyang Hospital, Capital Medical University, Beijing 100020, China.
Wang
Zhen-jun
ZJ
Zhao
Bo
B
Yang
Xin-qing
XQ
Wang
Dong
D
Wang
Jian-pin
JP
Tang
Xiu-ying
XY
Zhao
Fa
F
Hung
Yan-ting
YT
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
D042461:Vascular Endothelial Growth Factor A; D019001:Nitric Oxide Synthase; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9