RESUMO
Results of the deoxyuridine suppression test, a good marker for defining biochemical megaloblastosis caused by deficiency of folate and vitamin B12, became abnormal (greater than 10%) after 6 hours of administration of nitrous oxide anesthesia. 5-Formyltetrahydrofolate and methylcobalamin administration during nitrous oxide anesthesia have no remarkable effect on the correction of deoxyuridine suppression test values. On the other hand, 5-formyltetrahydrofolate and methylcobalamin administrated at the end of nitrous oxide anesthesia corrected the abnormal deoxyuridine suppression test values nearly to normal range within 1 hour.
Assuntos
Medula Óssea/metabolismo , Leucovorina/farmacologia , Óxido Nitroso/efeitos adversos , Vitamina B 12/análogos & derivados , Medula Óssea/efeitos dos fármacos , DNA/biossíntese , Desoxiuridina/metabolismo , Ácido Fólico/sangue , Humanos , Leucovorina/sangue , Óxido Nitroso/antagonistas & inibidores , Timidina/metabolismo , Fatores de Tempo , Vitamina B 12/sangue , Vitamina B 12/farmacologiaRESUMO
Hematopoietic and nonhematopoietic cell lines cultured in media containing either 5-methyltetrahydrofolate or 5-formyltetrahydrofolate grow well to the same extent. However, when these same cell lines are grown in the presence of nitrous oxide, selective growth inhibition can be shown for hematopoietic cells cultured in 5-methyltetrahydrofolate-containing media. These cells also demonstrated a decreased ability to suppress [3H]-thymidine incorporation into DNA in deoxyuridine suppression tests.
Assuntos
Linfoma de Burkitt/fisiopatologia , Leucemia Linfoide/fisiopatologia , Leucemia Mieloide Aguda/fisiopatologia , Melanoma/fisiopatologia , Óxido Nitroso/farmacologia , Neoplasias Gástricas/fisiopatologia , Linfócitos B/fisiologia , Divisão Celular/efeitos dos fármacos , Linhagem Celular , Replicação do DNA/efeitos dos fármacos , HumanosRESUMO
5-Methyltetrahydrofolate homocysteine methyltransferase activity in human bone marrow cells obtained from patients undergoing surgical operation became low after about 4 hr of nitrous oxide (N2O) anesthesia. The deoxyuridine suppression test performed on these bone marrow cells also became abnormal after about 6 hr of N2O anesthesia. The incorporation of [3H]thymidine into DNA in the bone marrow cells preincubated with methionine or methotrexate was much higher after N2O anesthesia than before anesthesia. Since N2O and methionine or methotrexate have a synergistic effect on depletion of functional folate, N2O alone or in combination with methionine or methotrexate might be of value for cancer treatment and deserve clinical trials.