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Rajapakse NW, Kuruppu S, Hanchapola I, Venardos K, Mattson DL, Smith AI, Kaye DM, Evans RG. Evidence that renal arginine transport is impaired in spontaneously hypertensive rats. Am J Physiol Renal Physiol 2012; 302:F1554-62. [DOI: 10.1152/ajprenal.00084.2011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Low renal nitric oxide (NO) bioavailability contributes to the development and maintenance of chronic hypertension. We investigated whether impaired l-arginine transport contributes to low renal NO bioavailability in hypertension. Responses of renal medullary perfusion and NO concentration to renal arterial infusions of the l-arginine transport inhibitor l-lysine (10 μmol·kg−1·min−1; 30 min) and subsequent superimposition of l-arginine (100 μmol·kg−1·min−1; 30 min), the NO synthase inhibitor NG-nitro-l-arginine (2.4 mg/kg; iv bolus), and the NO donor sodium nitroprusside (0.24 μg·kg−1·min−1) were examined in Sprague-Dawley rats (SD) and spontaneously hypertensive rats (SHR). Renal medullary perfusion and NO concentration were measured by laser-Doppler flowmetry and polarographically, respectively, 5.5 mm below the kidney surface. Renal medullary NO concentration was less in SHR (53 ± 3 nM) compared with SD rats (108 ± 12 nM; P = 0.004). l-Lysine tended to reduce medullary perfusion (−15 ± 7%; P = 0.07) and reduced medullary NO concentration (−9 ± 3%; P = 0.03) while subsequent superimposition of l-arginine reversed these effects of l-lysine in SD rats. In SHR, l-lysine and subsequent superimposition of l-arginine did not significantly alter medullary perfusion or NO concentration. Collectively, these data suggest that renal l-arginine transport is impaired in SHR. Renal l-[3H]arginine transport was less in SHR compared with SD rats ( P = 0.01). Accordingly, we conclude that impaired arginine transport contributes to low renal NO bioavailability observed in the SHR kidney.
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Affiliation(s)
- N. W. Rajapakse
- Department of Physiology, Monash University,
- Baker IDI Heart and Diabetes Institute, Melbourne, Australia; and
| | - S. Kuruppu
- Department of Biochemistry and Molecular Biology, Monash University, and
| | - I. Hanchapola
- Department of Biochemistry and Molecular Biology, Monash University, and
| | - K. Venardos
- Baker IDI Heart and Diabetes Institute, Melbourne, Australia; and
| | - D. L. Mattson
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - A. I. Smith
- Department of Biochemistry and Molecular Biology, Monash University, and
| | - D. M. Kaye
- Baker IDI Heart and Diabetes Institute, Melbourne, Australia; and
| | - R. G. Evans
- Department of Physiology, Monash University,
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