Table 2.

Changes in NaPi-IIb, PiT-1 and PiT-2 mRNA expression levels in the upper intestine with age in normal rats

Transporters	4 weeks old	9 weeks old	15 weeks old
NaPi-IIb (mmol/mol villin-1)	63.8 ± 3.9	18.9 ± 3.5*	7.6 ± 1.5*
PiT-1 (mmol/mol villin-1)	12.4 ± 2.0	9.2 ± 1.7	14.9 ± 1.8
PiT-2 (mmol/mol villin-1)	0.26 ± 0.05	0.17 ± 0.05	0.31 ± 0.12

Values are expressed as mean ± SE (n = 12).

^*P < 0.05, significant difference versus 4 weeks old.