Abstract
To facilitate study, a chemical of the acridan class was given to rats to increase the frequency of vacuolated lymphocytes. The chemical produced inanition and starvation, but this effect per se did not increase the vacuolation. In Wright-Giemsa-stained smears generally clear vacuoles up to 2 μm in diameter were the same as those that occur at a very low frequency in apparently normal animals and humans, in some chemical intoxications in animals, and in some natural diseases of humans. The use of several histochemical stains failed to further characterize the nature of the vacuoles. Samples were then processed for electron microscopic examination. By this procedure, the lymphocytes had membranous cytoplasmic bodies correlated with the presence of the vacuoles. The change appeared identical to light microscopic vacuoles and ultrastructural bodies described in chloroquine intoxication of rats and pigs and certain neurolipidoses of humans.