Relationship between ribo- and deoxyribonucleotide concentrations and biological parameters in cultured Chinese hamster ovary cells.

The relationship between ribo- and deoxyribonucleotide concentrations, growth rate and cell visibility has been studied. Nucleotide pools were manipulated using mycophenolic acid, pyrazofurin, phosphonoacetyl-L-aspartate (PALA) or thymidine. Growth rate, cell viability, nigrosin exclusion, progression through the cell cycle, and the rates of nucleic acid synthesis were measured. The observed qualitative relationships between nucleotide concentrations and growth rate can be rationalized in terms of the effects of changes in substrate availability on nucleic acid synthesis. However, there is no discernible relationship between changes in nucleotide concentrations and the loss of cell viability. More detailed studies will be required to elucidate each step in the complex process leading from the initial changes in nucleotide concentrations to cell death.