| First Author | Segawa H | Year | 2004 |
| Journal | Am J Physiol Renal Physiol | Volume | 287 |
| Issue | 1 | Pages | F39-47 |
| PubMed ID | 14996670 | Mgi Jnum | J:95427 |
| Mgi Id | MGI:3525976 | Doi | 10.1152/ajprenal.00375.2003 |
| Citation | Segawa H, et al. (2004) Intestinal Na-P(i) cotransporter adaptation to dietary P(i) content in vitamin D receptor null mice. Am J Physiol Renal Physiol 287(1):F39-47 |
| abstractText | Recent studies suggest that vitamin D may play a role in intestinal Na(+)-dependent phosphate transport adaptation to variable levels of dietary P(i). Therefore, the goal of the current study was to assess Na(+)-dependent P(i) cotransport activity in transgenic mice to determine whether vitamin D is an essential mediator of this process. Intestinal brush-border membrane (BBM), Na(+)-dependent P(i) cotransport activity was significantly decreased in vitamin D receptor (VDR) null [VDR (-/-)] mice compared with wild-type (VDR+/+) mice. While intestinal Na-P(i) cotransporter (type IIb) mRNA levels were similar in VDR (-/-) and VDR (+/+) mice, type IIb Na-P(i) cotransporter protein expression was markedly suppressed in VDR (-/-) mice compared with VDR (+/+) mice. Furthermore, Na-P(i) cotransport activity in renal BBM was similar in VDR (-/-) and VDR (+/+) mice, but type IIa Na-P(i) cotransporter protein expression was decreased in VDR (-/-) mice. After administration of a low-P(i) diet, type IIb protein expression was significantly increased in VDR (+/+) and VDR (-/-) mice, and type IIb protein expression was present in the intestinal BBM of VDR (-/-) mice. These data demonstrate that intestinal Na-P(i) cotransport adaptation to a low-P(i) diet occurs independently of vitamin D. |
