LOCALIZATION OF UROKINASE-TYPE PLASMINOGEN-ACTIVATOR MESSENGER-RNA IN THE NORMAL MOUSE BY INSITU HYBRIDIZATION

The histological distribution of urokinase-type plasminogen activator (u-PA) mRNA was analyzed in normal mouse tissue by in situ hybridization with anti-sense RNA transcribed from three different subclones of a mouse u-PA cDNA. Hybridization signal was found over a distinct fibroblast-like cell in the lamina propria of the gastrointestinal tract, over proximal, distal, and collecting tubules of the kidney, and over the epithelium of the bladder, ductus deferens, and epididymis. No hybridization signal was found over cells of the lung, pancreas, liver, adrenal, pituitary, cerebrum, hypothalamus, cerebellum, sciatic nerve, and striated muscle, nor over endothelial cells in any tissue investigated. The lack of u-PA mRNA in lung tissue was confirmed by Northern analysis and is in contrast to the high amounts of u-PA protein found in this tissue.