Renal oxygenation changes during water loading as evaluated by BOLD MRI: Effect of NOS inhibition
Article first published online: 29 MAR 2011
Copyright © 2011 Wiley-Liss, Inc.
Journal of Magnetic Resonance Imaging
Volume 33, Issue 4, pages 898–901, April 2011
How to Cite
Haque, M., Franklin, T. and Prasad, P. (2011), Renal oxygenation changes during water loading as evaluated by BOLD MRI: Effect of NOS inhibition. J. Magn. Reson. Imaging, 33: 898–901. doi: 10.1002/jmri.22509
- Issue published online: 29 MAR 2011
- Article first published online: 29 MAR 2011
- Manuscript Accepted: 7 JAN 2011
- Manuscript Received: 21 OCT 2010
- National Institutes of Health. Grant Number: R01-DK053221
- nitric oxide;
- water diuresis;
- renal medullary oxygenation
To demonstrate a possible role for endogenous release of nitric oxide in determining the response of water loading on intrarenal oxygenation as evaluated by blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI).
Materials and Methods:
Twelve Sprague Dawley rats (weight 344.9 ± 40.6 g) were equally divided into two groups, A and B. Water loading was implemented by continuous infusion of hypotonic saline containing glucose (0.25% NaCl, 0.5% glucose). Rats in group A were subject to water loading alone, while group B rats were dosed with N-nitro-L-arginine methyl ester, (L-NAME) (10.0 mg/kg) prior to water loading. T2*-weighted images of the kidneys were obtained on a Siemens 3T Verio MRI scanner using a multiple gradient recalled echo (mGRE) sequence.
Consistent with previous reports, group A exhibited a significant decrease in medullary R2* during water loading (40.64 ± 1.10 s−1 to 34.68 ± 1.49 s−1, P < 0.05). On the other hand, in group B there was no decrease in R2* during water loading (48.11 ± 2.38 s−1 to 51.06 ± 2.18 s−1). The increased prewater loading R2* is due to the pretreatment with L-NAME (40.82 ± 3.23 s−1 to 48.11 ± 2.38 s−1, P < 0.05).
Our data suggest for the first time a role for endogenous nitric oxide in determining the response of renal medullary oxygenation to water loading. J. Magn. Reson. Imaging 2011;33:898–901. © 2011 Wiley-Liss, Inc.