Protective mechanisms of the angiotensin II type 1 receptor blocker candesartan against cerebral ischemia : in-vivo and in-vitro studies

BACKGROUND: Angiotensin II type 1 (AT1) receptor blockers decrease ischemia by mechanisms dependent on and independent of arterial blood pressure in hypertensive rats and AT1-R knockout mice, respectively. However, the detailed mechanisms underlying the effects of AT1 receptor blockers remain unclear.

AIMS: To elucidate the systemic and focal effects of AT1 receptor blockers against cerebral ischemia in in-vivo and in-vitro studies.

METHODS: Normotensive Wistar rats were treated for 2 weeks with 0.5 or 1 mg/kg candesartan cilexetil and then subjected to 2-h middle cerebral artery occlusion-reperfusion. Human umbilical endothelial cells were stimulated with the active form of candesartan and angiotensin II in the absence and presence of an angiotensin II type 2 (AT2) receptor antagonist.

RESULTS: In candesartan-pretreated hypotensive and nonhypotensive rats, blood pressure was moderately increased during middle cerebral artery occlusion and fell gradually to the baseline after the reperfusion; it remained elevated in the control even after the reperfusion occlusion. Candesartan treatment resulted in a decrease in the cortical infarct volume and oxidative damage, the hypoxic status was improved, and the expression of repair-associated and growth-associated proteins in the cortical penumbra was augmented. Candesartan also increased the eNOS mRNA level and the lumen size of the middle cerebral artery. In human umbilical endothelial cells, candesartan increased the eNOS protein level AT2-R dependently, inhibited the expression of nicotinamide adenine dinucleotide phosphate oxidase subunits and angiotensin II-induced intracellular reactive oxygen species and nitric oxide, and promoted the extracellular release of nitric oxide, suggesting that it augmented the bioavailability of nitric oxide.

CONCLUSION: Among the mechanisms candesartan exerts in its protection against cerebral ischemia, restoration of endothelial function may represent an attractive therapeutic goal to address cerebral ischemia.

Medienart:

E-Artikel

Erscheinungsjahr:

2008

Erschienen:

2008

Enthalten in:

Zur Gesamtaufnahme - volume:26

Enthalten in:

Journal of hypertension - 26(2008), 7 vom: 01. Juli, Seite 1435-45

Sprache:

Englisch

Beteiligte Personen:

Liu, Hao [VerfasserIn]
Kitazato, Keiko T [VerfasserIn]
Uno, Masaaki [VerfasserIn]
Yagi, Kenji [VerfasserIn]
Kanematsu, Yasuhisa [VerfasserIn]
Tamura, Tetsuya [VerfasserIn]
Tada, Yoshiteru [VerfasserIn]
Kinouchi, Tomoya [VerfasserIn]
Nagahiro, Shinji [VerfasserIn]

Links:

Volltext

Themen:

31C4KY9ESH
Angiotensin II Type 1 Receptor Blockers
Benzimidazoles
Biphenyl Compounds
Candesartan cilexetil
EC 1.14.13.39
Journal Article
Nitric Oxide
Nitric Oxide Synthase Type II
Nitric Oxide Synthase Type III
Nos3 protein, rat
R85M2X0D68
Reactive Oxygen Species
Research Support, Non-U.S. Gov't
Tetrazoles

Anmerkungen:

Date Completed 23.10.2008

Date Revised 18.03.2022

published: Print

Citation Status MEDLINE

doi:

10.1097/HJH.0b013e3283013b6e

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM180186620