Bone marrow and spleen morphology following haemolytic anaemia in adult laboratory rats of various age groups.

We induced toxic-haemolytic events in 8, 11 and 29-w-old rats after single dose of nitrobenzene, 3-chloro-4-benzyloxyphenacetic acid and phenacetin administered orally. Large individual variability of haematological changes in rat marrow and spleen morphology was found. The use of groups of laboratory rats of different age significantly modified reactions in characteristics investigated but common simple age-related changes were not clearly demonstrated.