2024-03-29T02:24:20Z
https://niigata-u.repo.nii.ac.jp/oai
oai:niigata-u.repo.nii.ac.jp:00006609
2022-12-15T03:39:55Z
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471:537:568:643
Structural Differences of Arterial Walls Which are Either Vulnerable or Resistant to Atherosclerosis
Structural Differences of Arterial Walls Which are Either Vulnerable or Resistant to Atherosclerosis
Yoshida, Yoji
53648
Sue, Wang
53649
Yamane, Tetsu
53650
Okano, Mitsuji
53651
Oyama, Toshio
53652
Mitsumata, Masako
53653
Suda, Koichi
53654
Yamaguchi, Takami
53655
Ooneda, Genju
53656
In order to clarify the mechanism of different vulnerability to atherogenesis between the apical and lateral wall at a branching, both regions of the inferior mesenteric artery in human autopsy cases were investigated electron microscopically. The lateral wall has been accepted as the most preferential site for the disease, in contrast with the apex which is considered the most resistant by many investigators. In newborns intimal thickness in the apex was greater than in the lateral wall due mainly to proliferation of SMC. After the 3rd decade, collagen fibers drastically increased in the whole apex and smooth muscle cells embedded between collagen fibers modulated their phenotype from synthetic to contractile. In the lateral intima smooth muscle cells still remained in the synthetic type. The synthetic smooth muscle cells have been considered to be capable of proliferation in the arterial wall. The lateral intima was generally abundant in proteoglycans and lacked collagen (including subendothelial basement membranes) as well as elastic fibers, particularly in the upper part of the intima. This structural difference could bring favorable conditions for atherogenesis. Results of in vitro studies revealed that collagen gel containing types I and III suppressed proliferation of SMC and changed their phenotype from synthetic to contractile. Therefore, laminar high shear stress would give resistance to the arterial wall in atherogenesis through phenotypic change of SMC. Although rabbits showed different preferential regions for lipid deposition, it developed mostly in areas covered by oval round endothelial cells which might be exposed to relatively low mean shear stress. These shapes of endothelial cells were seen already in intact rabbits. Therefore, hemodynamic forces may play a very important role in determining the vulnerability of arterial walls to atherogenesis.
departmental bulletin paper
Niigata University School of Medicine
1990-03
application/pdf
Acta medica et biologica
38(Supplement)
1
19
Acta medica et biologica
AA00508361
05677734
https://niigata-u.repo.nii.ac.jp/record/6609/files/38(Suppl.)_1-19.pdf
eng