Abstract: Objective To explore the effects of gastrin on the expression of 1,25(OH)2D3-membrane associated rapid response
steroid (1,25D3-MARRS) binding protein in rat intestinal epithelium. Methods SD rats received intraperitoneal injections of
gastrin, omeprazole or physiological saline. The protein expression of 1,25D3-MARRS binding protein in SD rat intestinal was
determined with Western blotting and immunohistochemistry, and its mRNA levels determined by RT-PCR. The serum
calcium and phosphate levels in the rats were also detected. Results Immunohistochemistry showed that 1,25D3-MARRS
binding protein was expressed mainly in the nuclei, cytoplasm and membrane of the intestinal epithelial cells. Both the protein
and mRNA expression levels of 1,25D3-MARRS binding protein were up-regulated after treatments with gastrin and
omeprazole (P<0.05), but the serum calcium and phosphate concentrations showed no obvious increase. Conclusion 1,
25D3-MARRS binding protein, which is widely expressed with versatile functionalities, is regulated by gastrin and shows high
potentials in the study of gastrointestinal diseases.