Permeability characteristics of the rat urinary bladder in experimental cystitis and after overdistension.

The permeability characteristics of the rat urinary bladder were investigated in experimental cystitis achieved by xylene/Escherichia coli, after dimethylsulfoxide (DMSO) exposure and 3 and/or 10 days after overdistension. The changes were found to be comparable between experimental cystitis and DMSO treatment, whereas those after overdistension were specifically different in nature. Passive increases in NaCl permeability were shown to be accompanied by functional, metabolic impairment of the urothelium. It has been suggested that the concept of an almost impermeable 'blood-urine barrier' is completely misleading under these circumstances. This should be taken into account in future clinical considerations.