Effects of ovariectomy on intestinal alkaline phosphatase expression in rats

The aim of this study was to investigate the effects of ovariectomy (OVX) on intestinal alkaline phosphatase (ALP) activity in rats. The calcium (Ca) and phosphorus (P) contents and the mechanical strength of bone were decreased significantly by OVX. Two kinds of mRNAs of rat intestinal ALP (RTIN-1 and RTIN-2) were detected by reverse transcription-polymerase chain reaction (RT-PCR). In OVX rats, the level of RTIN-2 mRNA was lowered significantly, while that of RTIN-1 mRNA did not change. This result was compatible with the results of enzymatic activity. This finding suggests the possibility that OVX affects bone metabolism not only directly but also in an indirect way through an intestinal Ca and/or P metabolism via regulation of intestinal RTIN-2 ALP expression.