ENDOSCOPIC CONFOCAL FLUORESCENCE MICROSCOPY OF NORMAL AND TUMOR BEARING RAT BLADDER

ABSTRACT 

Purpose

We evaluated the possibility of performing endoscopic fiber-optic confocal microscopy in a rat bladder model and we distinguished different cell types.

Material and Methods

Rhodamine 123 (Molecular Probes, Eugene, Oregon) (100 μM) was instilled for 30 minutes in 5 tumor bearing rat bladders (AY27). Five normal rats served as controls. A Cell-vizio™ confocal microscopy fiber was placed transurethrally in contact with normal or transformed bladder wall. Frozen sections were obtained from the same spots and subjected to conventional fluorescence microscopy and anatomical-pathological analysis.

Results

The different cells types present in rat epithelium (umbrella, intermediate and basal cells) could easily be identified with the Cell-vizio™ device due to their differences in morphology and fluorescence intensity. Individual AY-27 cells could not be demarcated due to the strong fluorescence signal but the entire tumor appeared as a brightly homogenous fluorescent blot surrounded by small inflammatory cells.

Conclusions

We report the feasibility of endoscopic, in vivo, fiber-optic confocal microscopy in the rat bladder. We distinguished tumors from normal epithelium and visualized the different epithelial cell types in nontransformed rat bladder epithelium.

Key Words:  bladder , bladder neoplasms , diagnosis , microscopy, fluorescence , endoscopy