Ultrastructural changes of leukemic cells treated with antileukemic agents.

Part 2. Effects of daunomycin on mouse L1210 cells (ascites form).

Abstract

Ultrastructures of mouse L1210 leukemic cells (ascites form) treated with daunomycin were investigated. Cells grown intraperitoneally in BDF₁ mice were used. Ten minutes to 6 hours following the intraperitoneal injection of daunomycin (8mg/kg. b. w. ), cells were obtained by centrifugation of ascites, fixed in aldehyde and/or osmium tetroxide, and processed for ultrastructural observation. Following treatment with daunomycin, nucleoli initially lost their network, i. e. nucleolonema. Then, findings such as clumping of interchromatinic particles, nucleolar segregation, and nucleolar condensation manifested themselves. Some ultrastructural changes were observed in the cytoplasm also, such as dissociation of polysome pattern, increased number of activated lysosomes and vacuolization or disappearance of cristae in mitochondria. In some cases aggregated granules resembling interchromatinic particles were observed in the cytoplasm, which seemed to have been extruded from the nucleus.