| First Author | Tenenhouse HS | Year | 1993 |
| Journal | Pediatr Nephrol | Volume | 7 |
| Issue | 3 | Pages | 312-8 |
| PubMed ID | 8518105 | Mgi Jnum | J:14665 |
| Mgi Id | MGI:62829 | Doi | 10.1007/BF00853232 |
| Citation | Tenenhouse HS, et al. (1993) Renal adaptation to phosphate deprivation: lessons from the X-linked Hyp mouse. Pediatr Nephrol 7(3):312-8 |
| abstractText | The X-linked Hyp mutation, a murine homologue of X-linked hypophosphatemia in humans, is characterized by renal defects in phosphate reabsorption and vitamin D metabolism. In addition, the renal adaptive response to phosphate deprivation in mutant Hyp mice differs from that of normal littermates. While Hyp mice fed a low phosphate diet retain the capacity to exhibit a significant increase in renal brush-border membrane sodium-phosphate cotransport in vitro, the mutants fail to show an adaptive increase in maximal tubular reabsorption of phosphate per volume of glomerular filtrate (TmP/GFR) in vivo. Moreover, unlike their normal counterparts, Hyp mice respond to phosphate restriction with a fall in the serum concentration of 1,25-dihydroxyvitamin D [1,25(OH)2D] that can be ascribed to increased renal 1,25(OH)2D catabolism. The dissociation between the adaptive brush-border membrane phosphate transport response and the TmP/GFR and vitamin D responses observed in Hyp mice is also apparent in X-linked Gy mice and hypophysectomized rats. Based on these findings and the notion that transport across the brush-border membrane reflects proximal tubular function, we suggest that the adaptive TmP/GFR response requires the participation of 1,25(OH)2D or a related metabolite and that a more distal segment of the nephron is the likely target for the 1,25(OH)2D-dependent increase in overall tubular phosphate conservation. |
