Lipid composition of the plasma membrane isolated from normal and precancerous rat bladder epithelium.

Four-week-old Wistar strain rats were given 0.05% N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) solution for 12 weeks and used as a precancerous model. Sixteen-week-old rats of the same strain were used as controls. Plasma membranes (PMs) were prepared from normal and precancerous bladder epithelium. The lipid content and the fatty acid compositions of total lipids, phospholipids, and their subclasses were analysed. The following observations were made: 1) Precancerous PMs had longer chains composed of more unsaturated fatty acids than the normal ones. 2) There were high amounts of arachidonic acid in rat bladder epithelium, and it accounted for more than fifty percent of phosphatidylethanolamine. PMs of precancerous epithelium had more arachidonic acid than those of the normal epithelium. These findings may be useful for the early detection of precancerous epithelium.