Fine structural evidence of increased endothelial permeability in chronic lathyrism.

The endothelium of the thoracic aorta of Wistar rats intoxicated with Beta-Aminopropionitrile (BAPN) for 9 weeks was studied. The animals were sacrificed at intervals, from the first to the 9th week of the treatment and 1, 2 and 3 months after the end of the treatment. Changes in the endothelial cells were studied by electron microscopy after staining with uranyl acetate and lead citrate, after impregnation with lanthanum. BAPN increased endothelial permeability, pinocytosis was more active in treated rats than controls, the intercellular junctions widened and cytoplasmic lesions with cell necrosis occurred. These intimal changes were comparable to those observed in man during ageing and in arteriosclerosis.