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.