Effects of methylprednisolone on the intercellular communication in renal tubulointer-stitial fibroblasts in mice

Gap Junctions are important intercellular membrane channels that provide a pathway for intercellular exchange of ions and small molecules. In the present study, we observed the effect of Methylprednisolone（MP） on the functions of gap junctions in renal tubulointerstitial fibroblasts using fluorescence bleaching technique under laser confocal scanning microscopy（LCSM）. The fibroblasts were cultured in 37℃, 5% CO₂ for 24 hours and then were treated with MP in concentrations of 0, 100,200,300 and 400 μg/ml respectively. The treated cells were cultured for another 6 hours and stained with 1×10 ^-6 M 5-（and -6）carboxyfluorescein diacetate （CFDA） for 15 minutes. The fluorescence of the cells were bleached with laser and the time and rate of fluorescence recovery were recorded. The parameters of LCSM were as following: Laser power 500mW, step size 1.00 μm, scanning strength 10%, bleach strength 50% and stage speed 20.00 mm/sec. The results showed that fluorescence recovery in the fibroblasts appeared after bleaching within a minute. MP can inhibit the fluorescence recovery rate of the cells after laser bleaching at the time of 9.2 minute. Our data suggest that MP may inhibit the intercelluar communication via the pathway of changing the function of Gap junctions.