Effects of angiotensin II type 1 receptor blockade on the systemic blood nitric oxide dynamics in Nomega-nitro-L-arginine methyl ester-treated rats.
We previously succeeded in measuring the nitrosylhemoglobin (HbNO) level as an index of blood nitric oxide (NO) by the electron paramagnetic resonance (EPR) HbNO signal subtraction method. In this study, we examined the effects of olmesartan, an angiotensin II type 1 receptor blocker (ARB), on NO dynamics in N(omega)-nitro-L-arginine methyl ester (L-NAME)-treated rats by the EPR-subtraction method. Oral administration of L-NAME for 2 weeks induced serious hypertension, and the HbNO concentration was reduced to 37.6% of the level in controls. Coadministration of olmesartan improved hypertension and increased the blood HbNO concentration of L-NAME-treated rats. In contrast, coadministration of hydralazine improved hypertension but did not affect the blood HbNO concentration. In conclusion, our findings suggested that chronic administration of olmesartan ameliorated the endothelial dysfunction in L-NAME-treated rats.
Kanematsu
Yasuhisa
Y
Department of Pharmacology, Institute of Health Biosciences, the University of Tokushima Graduate School of Medical Sciences, Japan.
Tsuchiya
Koichiro
K
Ohnishi
Hideki
H
Motobayashi
Yuki
Y
Izawa
Yuki
Y
Ishihara
Manabu
M
Ishizawa
Keisuke
K
Abe
Shinji
S
Kawazoe
Kazuyoshi
K
Tamaki
Toshiaki
T
D047228:Angiotensin II Type 1 Receptor Blockers / Q000494:pharmacology*; D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D004578:Electron Spin Resonance Spectroscopy; D004730:Endothelium, Vascular / Q000187:drug effects / Q000503:physiopathology; D006339:Heart Rate / Q000502:physiology; D006439:Hemodynamics / Q000187:drug effects / Q000502:physiology; D006454:Hemoglobins / Q000032:analysis; D006830:Hydralazine / Q000494:pharmacology; D006973:Hypertension / Q000097:blood* / Q000139:chemically induced / Q000503:physiopathology*; D007093:Imidazoles / Q000494:pharmacology*; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000009:adverse effects; D009569:Nitric Oxide / Q000097:blood* / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013777:Tetrazoles / Q000494:pharmacology*
D047228:Angiotensin II Type 1 Receptor Blockers; D000959:Antihypertensive Agents; D006454:Hemoglobins; D007093:Imidazoles; D013777:Tetrazoles; C008657:nitrosyl hemoglobin; D006830:Hydralazine; D009569:Nitric Oxide; C437965:olmesartan; D019331:NG-Nitroarginine Methyl Ester