In situ localization of transforming growth factor‐β 1 mRNA in the rat kidney with Masugi nephritis

Masugi nephritis was induced in rats by the administration of nephrotoxic duck serum and, in their kidneys, the distributions of transforming growth factor-β 1 (TGF-β 1) mRNA, TGF-β 1, and macrophage antigenic marker were investigated. Kidney specimens were obtained at 3, 7, and 14 days after the injection. By in situ hybridization, TGF-β 1 mRNA was found to be localized in the cells of mesangial region from the early stage of nephritis. By the immunohistochemical stainings, TGF-β 1 was found to be localized in the cells of distal convoluted tubulus throughout the experiments and the macrophage antigenic marker was found to be localized in the occasional cells which were different from that contained TGF-β 1 mRNA. Our data indicate that TGF-β 1 mRNA is expressed by the resident glomerular cells and not by the migrating macrophages in rat kidney with Masugi nephritis. © 1994 Wiley-Liss, Inc.