2004 Fiscal Year Final Research Report Summary
Instability and remodeling of cerebral aneurysmal walls
| Project/Area Number |
15591528
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Cerebral neurosurgery
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| Research Institution | The University of Tokushima |
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Principal Investigator |
NAGAHIRO Shinji The University of Tokushima, Institute of Health Biosciences, Professor, 大学院・ヘルスバイオサイエンス研究部, 教授 (60145315)
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| Co-Investigator(Kenkyū-buntansha) |
SANO Toshiaki The University of Tokushima, Institute of Health Biosciences, Professor, 大学院・ヘルスバイオサイエンス研究部, 教授 (80154128)
SATOH Koichi The University of Tokushima, Institute of Health Biosciences, Associate Professor, 大学院・ヘルスバイオサイエンス研究部, 助教授 (90225938)
MATSUBARA Shunji Tokushima University, Hospital, Lecturer, 医学部・歯学部附属病院, 講師 (60294675)
SUZUE Atsuhiko The University of Tokushima, Institute of Health Biosciences, Assistant Professor, 大学院・ヘルスバイオサイエンス研究部, 助手 (60346608)
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| Project Period (FY) |
2003 – 2004
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| Keywords | aneurysm / smooth muscle cell / macrophage / BTEB2 / rat model / estrogen / ovary |
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| Research Abstract |
1)Unruptured and ruptured aneurysms were obtained at surgery or autopsy : control cerebral arteries at autopsy. The specimens were stained immunohistochemically with antibodies to α-smooth muscle actin, macrophages, and basic transcription regulatory element binding protein 2 (BTEB2). BTEB2-positive macrophages and smooth muscle cells were found in the luminal layer of large and giant unruptured aneurysms. This suggests that BTEB2 expression in the aneurysmal wall may play a role in the growth of aneurysms and may protect against their rupture.
2)We used vascular corrosion casts in order to detect early ultrastructural changes that occur at cerebral arterial bifurcations in response to hemodynamic stress and lead to cerebral aneurysms formation in rats subjected to aneurysm induction by ligation of the right common carotid artery and bilateral posterior renal arteries. Of the 20 operated rats, 11 (55%) developed aneurysmal changes ; 5 of these manifested changes of the endothelial cell imprints only (Stage I). In the other 6 rats, morphological changes of endothelial cells were associated with different grades of aneurysmal dilatation : 2 rats developed saccular dilatation of the arterial bifurcation (stage III) and 4 manifested intimal pad elevation (stage II).
3)New experimental aneurysmal model was developed in female rats subjected to estrogen deficiency by adding oophorectomy. Frequency of aneurysm formation in oophorectomized rats was 3 times higher than that in rats without oophorectomy. Frequency of aneurysm formation in rats treated with estrogen replacement reduced to the control level. The findings suggest that estrogen play an important role in the pathogenesis of cerebral aneurysms.
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