IMMUNOLOCALIZATION OF THE NEURAL CELL-ADHESION MOLECULE L1 IN NONPROLIFERATING EPITHELIAL-CELLS OF THE MALE UROGENITAL TRACT

The localization of the neural cell adhesion molecule L1 in the male u rogenital tract (including seminal vesicles and prostate) of the mouse and bull was investigated using immunocytochemical and immunochemical methods in order to better understand the function of this glycoprote in in non-neural tissues. L1 antibodies labeled non-myelinated nerves in all portions of the urogenital tract investigated. However, L1 immu noreactivity was also found between epithelial cells of several region s of the urogenital system including epididymal tail, deferent duct, e jaculatory duct and seminal vesicles. Some L1 immunoreactivity was als o demonstrated between epithelial cells of murine urinary bladder and urethra. The specificity of the immunoreaction was verified by western blots. There was no correlation between L1 expression and proliferati ng activity as revealed by double immunocytochemistry using various ma rkers of cell proliferation. This unexpected expression of L1 in nonne ural tissue is mainly restricted to non-proliferating epithelia of tho se portions of the urogenital tract that are derived from the Wolffian duct. It is suggested that L1 in these epithelia could enhance the me chanical resistance and reduce transepithelial permeability.