|
|
||||||||
1Department of Pharmacology and 2Department of Pediatrics, The University of Tokushima School of Medicine, and 3Department of Clinical Pharmacology and 4Department of Pharmacokinetics and Biopharmaceutics, Institute of Health Biosciences, The University of Tokushima, Tokushima, Japan
Submitted 2 June 2004 ; accepted in final form 22 December 2004
In this study, we investigated whether orally administered nitrite is changed to NO and whether nitrite attenuates hypertension in a dose-dependent manner. We utilized a stable isotope of [15N]nitrite (15NO2) as a source of nitrite to distinguish between endogenous nitrite and that exogenously administered and measured hemoglobin (Hb)-NO as an index of circulating NO in whole blood using electron paramagnetic resonance (EPR) spectroscopy. When 1 mg/kg Na15NO2 was orally administered to rats, an apparent EPR signal derived from Hb15NO (AZ = 23.4 gauss) appeared in the blood. The peak blood HbNO concentration occurred at the first measurement after intake (5 min) for treatment with 1 and 3 mg/kg (HbNO: 4.93 ± 0.52 and 10.58 ± 0.40 µM, respectively) and at 15 min with 10 mg/kg (HbNO: 38.27 ± 9.23 µM). In addition, coadministration of nitrite (100 mg/l drinking water) with N
-nitro-L-arginine methyl ester (L-NAME; 1 g/l) for 3 wk significantly attenuated the L-NAME-induced hypertension (149 ± 10 mmHg) compared with L-NAME alone (170 ± 13 mmHg). Furthermore, this phenomenon was associated with an increase in circulating HbNO. Our findings clearly indicate that orally ingested nitrite can be an alternative to L-arginine as a source of NO in vivo and may explain, at least in part, the mechanism of the nitrite/nitrate-rich Dietary Approaches to Stop Hypertension diet-induced hypotensive effects.
nitric oxide; hypertension; electron paramagnetic resonance
This article has been cited by other articles:
![]() |
Y. Kanematsu, K. Yamaguchi, H. Ohnishi, Y. Motobayashi, K. Ishizawa, Y. Izawa, K. Kawazoe, S. Kondo, S. Kagami, S. Tomita, et al. Dietary doses of nitrite restore circulating nitric oxide level and improve renal injury in L-NAME-induced hypertensive rats Am J Physiol Renal Physiol, November 1, 2008; 295(5): F1457 - F1462. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. T. Gladwin and D. B. Kim-Shapiro The functional nitrite reductase activity of the heme-globins Blood, October 1, 2008; 112(7): 2636 - 2647. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. M. Gonzalez, S. Shiva, P. S. Vincent, L. A. Ringwood, L.-Y. Hsu, Y. Y. Hon, A. H. Aletras, R. O. Cannon III, M. T. Gladwin, and A. E. Arai Nitrite Anion Provides Potent Cytoprotective and Antiapoptotic Effects as Adjunctive Therapy to Reperfusion for Acute Myocardial Infarction Circulation, June 10, 2008; 117(23): 2986 - 2994. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Kumar, B. G. Branch, C. B. Pattillo, J. Hood, S. Thoma, S. Simpson, S. Illum, N. Arora, J. H. Chidlow Jr., W. Langston, et al. Chronic sodium nitrite therapy augments ischemia-induced angiogenesis and arteriogenesis PNAS, May 27, 2008; 105(21): 7540 - 7545. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. S. Bryan, J. W. Calvert, J. W. Elrod, S. Gundewar, S. Y. Ji, and D. J. Lefer Dietary nitrite supplementation protects against myocardial ischemia-reperfusion injury PNAS, November 27, 2007; 104(48): 19144 - 19149. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Dejam, C. J. Hunter, C. Tremonti, R. M. Pluta, Y. Y. Hon, G. Grimes, K. Partovi, M. M. Pelletier, E. H. Oldfield, R. O. Cannon III, et al. Nitrite Infusion in Humans and Nonhuman Primates: Endocrine Effects, Pharmacokinetics, and Tolerance Formation Circulation, October 16, 2007; 116(16): 1821 - 1831. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. S. Isbell, M. T. Gladwin, and R. P. Patel Hemoglobin oxygen fractional saturation regulates nitrite-dependent vasodilation of aortic ring bioassays Am J Physiol Heart Circ Physiol, October 1, 2007; 293(4): H2565 - H2572. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. T. Gladwin, N. J. H. Raat, S. Shiva, C. Dezfulian, N. Hogg, D. B. Kim-Shapiro, and R. P. Patel Nitrite as a vascular endocrine nitric oxide reservoir that contributes to hypoxic signaling, cytoprotection, and vasodilation Am J Physiol Heart Circ Physiol, November 1, 2006; 291(5): H2026 - H2035. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. B. Manukhina, H. F. Downey, and R. T. Mallet Role of nitric oxide in cardiovascular adaptation to intermittent hypoxia. Experimental Biology and Medicine, April 1, 2006; 231(4): 343 - 365. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. B. Kim-Shapiro, A. N. Schechter, and M. T. Gladwin Unraveling the Reactions of Nitric Oxide, Nitrite, and Hemoglobin in Physiology and Therapeutics Arterioscler. Thromb. Vasc. Biol., April 1, 2006; 26(4): 697 - 705. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |