Saccharin-induced hyperplasia of the rat urinary bladder.

Dietary administration of sodium saccharin to male Fischer rats increased the rate of DNA synthesis of the urinary bladder epithelium as measured by tritiated thymidine uptake. A multifocal mild epithelial hyperplasia was induced, which was most readily detected by scanning electron microscopy, with pleomorphic microvilli present on many of the hyperplastic cells.