The recent finding that phosphate transporter proteins other than NaPis (members of the SCL34 family) might be involved in total body phosphate homeostasis, led us to study the expression of phosphate cotransporters NaPi-IIb, Pit-1, and Pit-2 along rat small and large intestine. Furthermore, we examined the effect of chornic high and low phosphate diets. Rats were given high (1,2% Pi) or low (0.2% Pi) Phosphate diet for five days and different segments of small and large intestine harvested for analysis. As expected, NaPi-IIb expression was mainly restricted to the initial part of the intestine, including duodenum and jejunum, and was upregulated during low phosphate diet.Surprisingly, a quite high expression level for this transporter was also found in the distal colon and also regulated by dietary intake. Pit-1 mRNA was found to be expressed in all intestinal segments analyzed. However, distal colon showed again the highest levels of expression and was the only site regulated by phosphate diets. In contrast, Pit-2 appears to be expressed only at low levels in all segements and is slightly upregulated during low phosphate diets. In summary, NaPi-IIb appears to be the major phosphate transporter in the small intestine. The distal colon may play a hitherto unrecognized role in phosphate absorption via NaPi-IIb and Pit-1.