Objective: To observe the changes of endothelin-1 (ET-1) concentration, immunohistochemical distribution, mRNA expression and localization in kidney of severe burn rat.
Methods: Wistar rats sustained with 30% TBSA III degree burn were divided randomly into 6 groups: normal control, 1, 3, 6, 12, and 24 postburn hour (PBH). The items studied were: the level of ET-1 in renal vein plasma and kidney tissue (cortex, outer medulla and inter medulla respectively), immunocytochemical distribution of ET-1 in kidney tissue by light and electron microscopy, mRNA expression of ET-1 in kidney by northern blot hybridization, localization and enumeration of mRNA expressiong cells of ET-1 by in situ hybridization.
Results: The rat kidney secretion and mRNA expression of ET-1 more evidently increased at 1, 3 PBH respectively than in normal control (P < 0.01), They distributed primarily on endothelial cells, glomerular mesangial cells. Tubular epithelial cells reached maximal mRNA expression and immunoreactivity at 3, 6 PBH respectively. Immune electron microscopic study demonstrated that ET-1 (gold particles) localized on the intracellular lumen surface of endothelium but on both apical and basal surfaces of epithelium.
Conclusion: Secretion and mRNA expression of ET-1 increased obviously in kidney in early stage after severe burn.