Involvement of apoptosis in the endotoxemic lesions of the liver and kidneys of piglets

The involvement of apoptosis was evaluated in lesions of endotoxemic piglet s. A single injection with E. coli O111:B4 lipopolysaccharide (LPS) induced foci of coagulative necrosis in the liver and kidneys. No significant chan ge was observed in these organs at 1.5 hr after LPS injection, but at 6 hr, epithelial cells with chromatin condensation or fragmentation and apoptoti c bodies were visible. Foci of coagulative necrosis were formed within 24 h r after LPS inoculation. In and adjacent to the necrotic foci, dead hepatoc ytes with nuclear condensation or fragmentation were scattered. These dead cells were positively stained by terminal deoxynucleotidyl transferase-medi ated dUTP-biotin nick end labeling (TUNEL) methods. Electronmicroscopy reve aled apoptotic cells with condensed or fragmented homogeneous nuclear chrom atin, and necrotic cells with irregularly destroyed nuclei and cytoplasmic membranes. Apoptotic cell death were also observed in parietal cells of the stomach and lymphocytes in the lymphatic system. DNA ladders with approxim ately 200-bp multimers were observed in hepatic. renal and thymic samples p repared after 6 and 24 hr of LPS injection by agarose gel electrophoresis. These results suggest that apoptosis is involved in the pathology of swine endotoxemia.