| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Department of Physiology & Biophysics, Georgetown University School of Medicine, Washington, DC, USA
2 Division of Renal Diseases and Hypertension, University of Colorado Health Sciences Center, Denver, CO, USA
* To whom correspondence should be addressed. E-mail: mulrones{at}georgetown.edu.
Regulation of phosphate (Pi) reabsorption, occurs through the up- and down-regulation of the renal type-II sodium Pi co-transporters (NaPi-2). Recently, "renal" NaPi2-type expression has been identified in areas of the brain. The present study determined if brain NaPi-2 is regulated by dietary Pi, and if the behavioral and renal adaptations to low dietary Pi are controlled centrally. NaPi-2-like expression in the 3rd ventricle and amygdala of juvenile Wistar rats was regulated by dietary Pi, as in the kidneys. When cerebrospinal fluid (CSF) Pi concentration was elevated by 3V injections of Pi in rats fed low Pi diet, the behavioral and renal adaptations to low Pi diet (LPD) were abolished. Most importantly, NaPi-2 expression was markedly reduced not only in the brain, but also renal proximal tubules, despite the low plasma Pi milieu. This was confirmed by the significant reduction in the transport maximum for Pi (from 8.1±0.2 in LPD + veh 3V to 1.7±0.1 µmol Pi/ml GFR in LPD + 3V Pi, P<0.001). These findings indicate that NaPi-2-like transporters in the brain are regulated by both dietary Pi and CSF Pi concentrations, and most significantly, that the central Pi milieu can regulate renal NaPi-2 expression. We hypothesize that central 3V NaPi-2 transporters may act as "Pi sensors" and help regulate both brain, and whole body Pi homeostasis.
This article has been cited by other articles:
|
|
 |
|
  B. S. Levine, C. R. Kleeman, and A. J. Felsenfeld The Journey From Vitamin D-Resistant Rickets to the Regulation of Renal Phosphate Transport Clin. J. Am. Soc. Nephrol., November 1, 2009; 4(11): 1866 - 1877. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. S. Alexander, A. Qu, S. A. Cutler, A. Mahajan, S. M. Lonergan, M. F. Rothschild, T. E. Weber, B. J. Kerr, and C. H. Stahl Response to dietary phosphorus deficiency is affected by genetic background in growing pigs J Anim Sci, October 1, 2008; 86(10): 2585 - 2595. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. V. Virkki, J. Biber, H. Murer, and I. C. Forster Phosphate transporters: a tale of two solute carrier families Am J Physiol Renal Physiol, September 1, 2007; 293(3): F643 - F654. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Y. Breusegem, N. Halaihel, M. Inoue, H. Zajicek, E. Lederer, N. P. Barry, V. Sorribas, and M. Levi Acute and chronic changes in cholesterol modulate Na-Pi cotransport activity in OK cells Am J Physiol Renal Physiol, July 1, 2005; 289(1): F154 - F165. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
