Ultrastructural evaluation of murine bladder epithelium exposed to verapamil.

The effect of single or multiple instillations of high verapamil concentrations on the cytoarchitecture of the bladder epithelium was assessed by electron microscopy. Ruthenium red was used to evaluate the surface mucopolysaccharide coats and the integrity of junctional complexes between luminal cells. No significant cytoplasmic change in the luminal or nonluminal cells was found in any experimental animals, nor was there a breakdown of the junctional complexes between luminal cells. These data suggest that verapamil may be safely used intravesically as adjunct to standard chemotherapy.