title: Role of angiotensin II type 1 receptor in cerebral aneurysm formation in rats.
abstract: Cerebral aneurysm (CA) causes catastrophic subarachnoid hemorrhage which is characterized by a high mortality and morbidity rate. CA is a common disease worldwide but to date there is no medical treatment against unruptured CAs. Thus, it is important to study the mechanisms of CA formation. Our previous report demonstrated that chronic inflammatory response in cerebral arterial bifurcation by hemodynamic stress deteriorated arterial walls and formed CA. Therefore, drugs with anti-inflammatory effects might effectively treat CA formation. As renin angiotensin system (RAS) is a major inflammatory cascade and related to various vascular diseases, including aortic aneurysms, the role of angiotensin (Ang) II type 1 receptor might contribute to the progression of CAs. However, in cerebral aneurysmal walls, Ang II type 1 receptor was not up-regulated. In addition, subcutaneously administered Ang II type 1 receptor blocker did not inhibit CA formation, nor inflammation in cerebral aneurysmal walls in rat models at a sub-suppressor dose. These results indicate that RAS might play a less important role in CA formation compared to aortic anuerysms or other vascular diseases. This suggests that there are different mechanisms between the pathogenesis of cereberal and aortic aneurysms.
authors.affiliation: Department of Neurosurgery, Kyoto University, Graduate School of Medicine, Kyoto 606-8507, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Aoki
authors.forename: Masaki
authors.initials: M
authors.lastname: Nishimura
authors.forename: Hiroharu
authors.initials: H
authors.lastname: Kataoka
authors.forename: Ryota
authors.initials: R
authors.lastname: Ishibashi
authors.forename: Takashi
authors.initials: T
authors.lastname: Miyake
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Takagi
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Morishita
authors.forename: Nobuo
authors.initials: N
authors.lastname: Hashimoto
mesh_terms: D047228:Angiotensin II Type 1 Receptor Blockers / Q000494:pharmacology / Q000627:therapeutic use; D000818:Animals; D018932:Chemokine CCL2 / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D002532:Intracranial Aneurysm / Q000188:drug therapy / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology*; D008264:Macrophages / Q000187:drug effects / Q000473:pathology; D020778:Matrix Metalloproteinase 2 / Q000235:genetics / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000235:genetics / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D044140:Receptor, Angiotensin, Type 1 / Q000378:metabolism*; D044139:Receptor, Angiotensin, Type 2 / Q000378:metabolism; D013777:Tetrazoles / Q000494:pharmacology / Q000627:therapeutic use; D014633:Valine / Q000031:analogs & derivatives / Q000494:pharmacology / Q000627:therapeutic use; D000068756:Valsartan
chemical_list: D047228:Angiotensin II Type 1 Receptor Blockers; D018932:Chemokine CCL2; D016328:NF-kappa B; D012333:RNA, Messenger; D044140:Receptor, Angiotensin, Type 1; D044139:Receptor, Angiotensin, Type 2; D013777:Tetrazoles; D000068756:Valsartan; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; D014633:Valine