Endothelial cell damage in piglet coronary artery after intravenous administration of E. coli endotoxin. A scanning and transmission electron-microscopic study.

E. Coli endotoxin was administered to 6 piglets from a litter of 10. Three days after the endotoxin stimulus 3 piglets showed definitive morphological evidence of endothelial damage to their left coronary artery. The proximal parts of the coronary artery were severely damaged. In scanning electron microscopy, the changes varied from disappearance of the microvilli to complete exfoliation of the endothelial cells. In cases of severe endothelial cell damage transmission electron microscopy revealed severe changes or even signs of cell death in the inner medial smooth muscle cells. Only of the piglets died prematurely. We are sufficiently encouraged to continue testing the theory that repeated endothelial cell damage initiates stenosing lesions in the coronary arteries.