title: Pathological Analysis of the Ruptured Vascular Wall of Hypoperfusion-induced Abdominal Aortic Aneurysm Animal Model.
abstract: Abdominal aortic aneurysm (AAA) is a vascular disease that results in the gradual dilation of the abdominal aorta and has a high rupture-related mortality rate. However, the mechanism of AAA rupture remains unknown. In our previous study, we established a novel AAA animal model (hypoperfusion-induced AAA rat model) with spontaneous AAA rupture. Using the hypoperfusion-induced AAA rat model, we demonstrated that the abnormal appearance of adipocytes in the vascular wall is associated with AAA rupture. However, pathological analysis of the rupture area has not been performed because it is particularly difficult to identify the rupture point. In this study, we succeeded in obtaining samples from the rupture point and performed a histological analysis of the ruptured area in the vascular wall in the hypoperfusion-induced AAA rat model. Adipocytes were observed along the AAA-ruptured area of the vascular wall. In the areas around the adipocytes, macrophage infiltration and protein levels of matrix metalloproteinases 2 and 9 were significantly increased and collagen-positive areas were significantly decreased, as compared with areas without adipocytes. The AAA diameter was correlated with the number of adipocytes in the vascular wall of the hypoperfusion-induced AAA rat model. On the other hand, serum triglyceride levels and serum total cholesterol levels were not correlated with the number of adipocytes in the vascular wall. These results suggest that local adipocyte accumulation in the vascular wall, not serum lipids, has an important role in AAA rupture.
authors.affiliation: Department of Applied Biological Chemistry, Graduate School of Agriculture, Kindai University.
authors.forename: Hirona
authors.initials: H
authors.lastname: Kugo
authors.affiliation: Department of Applied Biological Chemistry, Graduate School of Agriculture, Kindai University.
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Zaima
authors.affiliation: Department of Medical Physiology, Hamamatsu University School of Medicine.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Tanaka
authors.affiliation: Department of Applied Biological Chemistry, Graduate School of Agriculture, Kindai University.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Hashimoto
authors.affiliation: Department of Applied Biological Chemistry, Graduate School of Agriculture, Kindai University.
authors.forename: Chie
authors.initials: C
authors.lastname: Miyamoto
authors.affiliation: Department of Applied Biological Chemistry, Graduate School of Agriculture, Kindai University.
authors.forename: Ayaka
authors.initials: A
authors.lastname: Sawaragi
authors.affiliation: Department of Medical Physiology, Hamamatsu University School of Medicine.
authors.forename: Tetsumei
authors.initials: T
authors.lastname: Urano
authors.affiliation: Division of Vascular Surgery, Second Department of Surgery, Hamamatsu University School of Medicine.
authors.forename: Naoki
authors.initials: N
authors.lastname: Unno
authors.affiliation: Department of Applied Biological Chemistry, Graduate School of Agriculture, Kindai University.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Moriyama
mesh_terms: D017667:Adipocytes / Q000378:metabolism / Q000473:pathology*; D000818:Animals; D001012:Aorta, Abdominal / Q000166:cytology / Q000473:pathology*; D017544:Aortic Aneurysm, Abdominal / Q000209:etiology / Q000378:metabolism / Q000473:pathology*; D001019:Aortic Rupture / Q000209:etiology / Q000378:metabolism / Q000473:pathology*; D003094:Collagen / Q000378:metabolism; D004195:Disease Models, Animal; D008264:Macrophages / Q000473:pathology; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D017207:Rats, Sprague-Dawley
chemical_list: D003094:Collagen; D020778:Matrix Metalloproteinase 2; C522363:Mmp2 protein, rat; D020780:Matrix Metalloproteinase 9; C572337:Mmp9 protein, rat
keywords: abdominal aortic aneurysm; adipocyte; inflammation; lipid metabolism; rupture