An enzymatic activation of N-methyl-N-nitrose urea (MNU) was studied in microsomes, isolated from hepatoma 22a ascites cells, using a procedure which enabled to reveal the MNU enzymatic activation in mice liver microsomes. The MNU metabolic activation was not observed in hepatoma cell microsomes; at the same time, the MNU activation occurred when the cells were incubated under conditions of a suspension culture. The enzymes, participating in metabolic activation of MNU, were apparently arranged at the surface of the tumoral cells. Alkylation of MNU macromolecules was shown to be a two-step process. At the first step alkylation was due to spontaneous degradation of MNU and at the second step it was responsible for formation of active products as a result of MNU metabolic activation. MNU appears to induce synthesis of enzymes required of its metabolic activation in hepatoma 22a cells within 30 min.
Abakumova O.Yu., Kutsenko N.G. (1981) Metabolic activation of N-methyl-N-nitrosourea in tumor cells. Voprosy Meditsinskoi Khimii, 27(3), 383-387.
Abakumova O.Yu. et al. Metabolic activation of N-methyl-N-nitrosourea in tumor cells // Voprosy Meditsinskoi Khimii. - 1981. - V. 27. -N 3. - P. 383-387.
Abakumova O.Yu. et al., "Metabolic activation of N-methyl-N-nitrosourea in tumor cells." Voprosy Meditsinskoi Khimii 27.3 (1981): 383-387.
Abakumova, O. Yu., Kutsenko, N. G. (1981). Metabolic activation of N-methyl-N-nitrosourea in tumor cells. Voprosy Meditsinskoi Khimii, 27(3), 383-387.