Alcohol-induced vacuolization in bone marrow cells: ultrastructure and mechanism of formation.

Vacuolization has been known for two decades to occur in the cytoplasm and over the nuclei of the erythroid and myeloid precursors in bone marrows of patients with acute alcoholism. Electron microscopic examination of the marrows from four acute alcohol-intoxicated subjects disclosed that the vacuoles are present only in the cytoplasm and free of organized structure. Surface invagination of the cell membrane of erythroblasts leads to endocytosis and consequent vacuole formation. Cytoplasmic vacuolization of bone marrow cells was reproduced in vitro in 8 of 12 bone marrows from normal individuals when incubated for 6 hours or more in nutrient medium containing alcohol. The critical alcohol concentration for vacuolization was 62.5 mg/dl. The proportion of cells developing vacuoles appeared to correlate with the concentration of alcohol particularly above levels of 250 mg/dl.