The immunocytochemical localization of tumour necrosis factor and leukotriene in the rat kidney after treatment with lipopolysaccharide.

Abundant inflammatory cells such as polymorphonuclear leucocytes and macrophages accumulated and adhered to the endothelial surface of glomerular and intertubular veins and capillaries in rat kidneys after administration of bacterial lipopolysaccharide (LPS). There was also damage to both endothelial cells and proximal tubular cells, including intracytoplasmic oedema, and an increase in the number of lysosomes in the proximal tubular cells in the LPS-treated samples. Immunocytochemistry was used to demonstrate tumour necrosis factor (TNF) and leukotriene (LTR) in both LPS-treated and control samples. Immunoreactive LTR seen in the lysosomes of inflammatory cells attached to the endothelial cell surface may indicate the onset of endothelial cell damage. Positive immunoreactive TNF and LTR were seen on the endothelial cell surface only in the LPS-treated samples, indicating that TNF and LTR may enhance the adhesion of leucocytes to endothelium. Positive reactions of TNF and LTR in lysosomes of the mesangial cells suggest that lysosomes of such cells may be involved in the synthesis and storage of TNF and LTR. In addition to these reaction sites, lysosomes of proximal tubular cells were immunoreactive for LTR. These endogenous LTRs may be implicated in the degeneration of the proximal tubular cells.