[Effect of the spatial environment on the mitotic activity, size and protein content of Paramecium tetraurelia]

Cell proliferation, cell volume, protein components of paramecia and chemical analysis of culture medium were studied in Paramecium tetraurelia cultures placed in space environment. The space flight resulted in a marked stimulation of cell proliferation, an increase of cell volume, a decrease of mean protein components and changes of electrolytes in the culture medium.