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Helle F, Skogstrand T, Schwartz IF, Schwartz D, Iversen BM, Palm F, Hultström M. Nitric oxide in afferent arterioles after uninephrectomy depends on extracellular l-arginine. Am J Physiol Renal Physiol 2013; 304:F1088-98. [DOI: 10.1152/ajprenal.00665.2011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Uninephrectomy (UNX) causes hyperperfusion of the contralateral remaining kidney via increased nitric oxide (NO) synthesis. Although the exact mechanism remains largely unknown, we hypothesize that this would be localized to the afferent arteriole and that it depends on cellular uptake of l-arginine. The experiments were performed in rats 2 days (early) or 6 wk (late) after UNX and compared with controls (Sham) to study acute and chronic effects on NO metabolism. Renal blood flow was increased after UNX (21 ± 2 ml·min−1·kg−1 in sham, 30 ± 3 in early, and 26 ± 1 in late, P < 0.05). NO inhibition with Nω-nitro-l-arginine methyl ester hydrochloride (l-NAME) caused a greater increase in renal vascular resistance in early UNX compared with Sham and late UNX (138 ± 24 vs. 88 ± 10, and 84 ± 7%, P < 0.01). The lower limit of autoregulation was increased both in early and late UNX compared with Sham ( P < 0.05). l-NAME did not affect the ANG II-induced contraction of isolated afferent arterioles (AA) from Sham. AA from early UNX displayed a more pronounced contraction in response to l-NAME (−57 ± 7 vs. −16 ± 7%, P < 0.05) and in the absence of l-arginine (−41 ± 4%, P < 0.05) compared with both late UNX and Sham. mRNA expression of endothelial NO synthase was reduced, whereas protein expression was unchanged. Cationic amino acid transporter-1 and -2 mRNA was increased, while protein was unaffected in isolated preglomerular resistance vessels. In conclusion, NO-dependent hyperperfusion of the remaining kidney in early UNX is associated with increased NO release from the afferent arteriole, which is highly dependent on extracellular l-arginine availability.
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Affiliation(s)
- Frank Helle
- Renal Research Group, Institute of Medicine, University of Bergen, Bergen, Norway
- Department of Medicine, Haukeland University Hospital, Bergen, Norway
| | - Trude Skogstrand
- Renal Research Group, Institute of Medicine, University of Bergen, Bergen, Norway
| | - Idit F. Schwartz
- Department of Nephrology, Tel Aviv Sourasky Medical Center, Tel Aviv University, Sackler School of Medicine, Tel Aviv, Israel
| | - Doron Schwartz
- Department of Nephrology, Tel Aviv Sourasky Medical Center, Tel Aviv University, Sackler School of Medicine, Tel Aviv, Israel
| | - Bjarne M. Iversen
- Renal Research Group, Institute of Medicine, University of Bergen, Bergen, Norway
- Department of Medicine, Haukeland University Hospital, Bergen, Norway
| | - Fredrik Palm
- Division of Nephrology and Hypertension, Georgetown University, Washington, District of Columbia
- Department of Health and Medical Sciences, Linköping University, Linköping, Sweden; and
- Department of Medical Cell Biology, Division of Integrative Physiology, Uppsala University, Uppsala, Sweden
| | - Michael Hultström
- Renal Research Group, Institute of Medicine, University of Bergen, Bergen, Norway
- Department of Medicine, Haukeland University Hospital, Bergen, Norway
- Department of Medical Cell Biology, Division of Integrative Physiology, Uppsala University, Uppsala, Sweden
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