Objective:To detect the expressions

distribution and the significances of aquaporin 1（AQP1）

aquaporin 2（AQP2）and aquaporin 3（AQP3）in normal bladder tissues and bladder tumor tissues. Methods：The expression and distribution of AQP1、AQP2 and AQP3 were detected by S-P immunohistochemistry in 25 cases of bladder tumor tissues and normal bladder tissues of 25 cases. Results：The AQP1was sporadically expressed in the vascular endothelial cells of normal bladder tissues. The majority expression of AQP1 could be detected in the vascular endothelial cells of tumor cells. The expression of AQP1 was remarkably higher in tumor tissues than in normal bladder tissues. Sporadic expression of AQP2 could be detected in intercellular substance in both bladder tumor tissues and normal bladder tissues. The expression of AQP2 in both tumor tissues and normal bladder tissues had no significant difference.the expression of AQP3 was found mainly in the celluar membrane and periplasm of the mucous membrane in both bladder tumor tissues and normal bladder tissues. The expression of AQP3 was significantly higher in tumor tissues than in normal bladder tissues. Conclusion：The expression of AQP1 and AQP3 were highter in bladder tumor tissues than those in normal bladder tissues. It suggested that AQP1 and AQP3 might related with the formation and development of bladder tumor. But the mechanism need to be further studied.