RESUMO
The ultrastructural alterations in ventricular capillary endothelia of chick embryo heart treated with Adriamycin (ADRIA) are discussed. White-Leghorn chicken eggs on the third day of incubation (stage 18), were injected through the egg shell with 1 ml of ADRIA 5, ug/egg. Eggs were reincubated until day 15 (stage 41-42), at which time the embryos were sacrified and their hearts removed. Controls were injected with equal volume of saline solution. Unlike the controls, ADRIA treated embryonic ventricular capillary endothelia exhibited marked evidences of vascular damage. An apparent reduction of the cytoplasmic surface area of the abnormally dark and smooth endothelial cells was observed. Capillary endothelial alterations also included cell vacuolization, absence of cytoplasmic endothelial cell proyections and cytoplasmic blebs along capillar endothelial surface, most prominently along the free cell surface or lumen. The comparison of the ultrastructural characteristics between control and ADRIA-treated embryonic heart, may confirm ADRIA cardiotoxic effects during cardiogenesis. Capillary endothelium may be an alternative target of ADRIA and in appears likely that drug toxic effect may promote vascular damage