[Histochemical study of nucleic acids and proteins by cytophotometry and histoautoradiography in fibroblasts cultivated in hyperoxia (author's transl)].

Cells cultivated in 80% O2 were shown, by cytophotometric and histoautoradiographic methods, to undergo alterations concerning DNA, RNA and total proteins synthesis. These changes appear almost at the same time for all the above-named biological metabolites. Proliferative cell cycle undergoes changes before the blocking of the cells first in post-synthetic (G2) and then in pre-synthetic period (G1). It was also seen that protein synthetic rate of the cells is proportional to their DNA content, in other words tetraploid cells synthesize a double protein amount in comparison to diploid cells. Nucleolus labelling after Uridine-3H incorporation disappear the last under the effect of hyperoxia. Finally it was observed that DNA values (measured with scanning microscope) of prometaphase are higher than the mean values of other mitotic phases.