[Effect of enucleation on the structural and functional state of the cytoplasm in L cells]

The viability of cytochalasin-enucleated L-cells (cytoplasts) was investigated using autoradiography in addition to fluorescence and electron microscopy. L-cells were enucleated according to a modified Prescott's method (thermostabilized centrifugation, low centrifuge acceleration). Relatively mild conditions of enucleation permitted us to prolong the life-span of cytoplasts up to 24 hours. Soon after enucleation, the disaggregation of polyribosomes in cytoplasts takes place, reflecting, apparently, m-RNA degradation. The cytoplasts are shown to be able to live for 1--2 days with a completely stopped protein synthesis. Acridin orange staining and ultrastructural investigation showed lysosomal hypertrophy in senescent cytoplasts. The death of cytoplasts is suggested to be due to disruption of lysosomes.