Immunolocalization of CFTR, SLC26A6, CAII, CAXII and NHE1 in steroid-replaced ovariectomized rats. CFTR and SLC26A6 were localized mainly at the apical membrane under E influence. Meanwhile, CAII was expressed predominantly in the glandular epithelia under both E and P influence. CAXII was expressed at the apical and basolateral membranes of the luminal epithelia under P and E influences respectively. Meanwhile, NHE1 expression was high under P influence. Objectives 10X and 100X were used to observe the uterine sections under light microscope. No staining was observed in the section pre-incubated with non-immune normal serum which acts as a negative control. E: 0.2µg 17β-oestradiol, P: 4mg progesterone, E+P: 0.2 µg 17β-oestradiol + 4mg progesterone Arrow: apical membrane, arrowhead: basolateral membrane L: lumen, Gl: gland.