The toxicopathology of Prudhoe Bay crude oil in chicken embryos.

Microliter amounts of Prudhoe Bay crude oil were applied to the shell of fertile leghorn chicken eggs on Day 9 of incubation. Gross and microscopic pathological changes were examined in embryos surviving 4 days after exposure. Gross lesions seen consistently were extensive edema, superficial zones of pale hepatic tissue, distension of the heart, and enlargement of the spleen. Histologically, the pale liver tissue corresponded to areas of hepatocyte necrosis. Additional histological lesions were cellular casts and mineralization in the renal tubules, distension of the glomerular capillaries, and accumulation of hematopoietic tissue in the liver and spleen. Dose-related increases in the number of mitotic figures in hepatocytes and in weights of liver, spleen, and heart were observed.