Passive membrane properties of single epididymal epithelial cells. (A) Examples of epithelial cells isolated from rat cauda epididymis after being reharvested from overnight culture on a dish before patch-clamp experiments. Only single cells were selected for patch-clamp recording. Arrows indicate epididymal epithelial cells (presumably principal cells or clear-like cells), and asterisks indicate no-microvilli cells, from which patch-clamp recordings were also done but the data were not presented. Insets show polarized distribution of intracellular contents in a principal cell. (B) Immunofluorescence detection of TRPV6 in fixed isolated epithelial cells showing typical example of a cell sharing the features of principal cells with positive staining (arrow). (C) Transmitted light microscopy image of the same cells (arrow). (D) Passive membrane properties of single rat epididymal cells as shown in A. (E) Images showing examples of principal cells isolated from rat cauda epididymis after day 0–4 cultures. Arrows indicate the identified principal cells in earlier culture days, whereas on later days, cells showed very different morphology. The typical current patterns and corresponding I-V plots as well as the membrane properties in different culture days are also shown. Numbers of cells tested are shown within bars. #, P < 0.05; ###, P < 0.001; ns, no significant difference versus appropriate controls using one-way ANOVA with Bonferroni post-hoc test. Bars: (A) 20 µm; (B and C) 10 µm. Error bars represent SEM.