Effect of N-methyl-N-nitrosourea on the protein-synthesizing system in mouse liver and hepatoma 22a cells.

SUMMARY A single injection of nitrosomethylurea (80 mg/kg body weight) to mice bearing hepatoma 22a led to an injury of the main components of the protein-synthesizing system (poly ribosomal complex and soluble factors of the cell sap) in liver and hepatoma cells. In liver cells of adult animals, the activity of the protein-synthesizing system returns to a normal level 5 to 15 hr after injection, while in hepatoma the process is irreversi ble for at least 48 hr. These results were confirmed and extended in experiments conducted in vitro with cell-free protein-synthesizing systems.