RESUMEN
Effects of photofrin II (PII) and light on the intra cellular nucleotide levels have been investigated using BHK-21 cell line. Results indicate that lower concentrations of photofrin II in dark increases ATP levels in a non linear manner, however, there has been no change in energy charge and levels of other nucleotides. Photoirradiation of PII-treated cells leads to a significant reduction in ATP levels and energy charge along with an increase in ATP breakdown products like ADP and AMP. The phosphorylation potential [ATP]/[ADP][Pi] also reduces upon photoirradiation of PII treated cells. Incubation conditions like pH of the medium and temperature modulate the cellular responses to a great extent.
Asunto(s)
Nucleótidos de Adenina/metabolismo , Animales , Línea Celular , Cricetinae , Éter de Dihematoporfirina/farmacología , Metabolismo Energético/efectos de los fármacos , Concentración de Iones de Hidrógeno , Luz , Fotoquimioterapia , TemperaturaRESUMEN
Effects of gamma-rays and glucose analogs, 2-deoxy-D-glucose (2-DG), 5-thio-D-glucose (5-TG) and 3-O-methyl glucose (3-O-MG) on cellular energy metabolism have been studied in a cell line, derived from a human cerebral glioma, by analysing intermediates of glycolysis and some important nucleotides (ATP, NAD etc.) using the technique of isotachophoresis. Gamma-irradiation induced a transient decrease in the nucleotide levels accompanied by an accumulation of sugar phosphates, the nucleotide levels recovering in a few hours post-irradiation. 2-DG inhibited glycolysis and reduced the nucleotide levels of irradiated as well as unirradiated cells in a concentration-dependent manner both in presence and absence of respiration, whereas 5-TG and 3-O-MG did not show significant effects in the presence of respiration. Reduced energy status observed with 2-DG under respiratory proficient conditions was completely reversed in 2 hr following its removal, whereas such a recovery was not observed in the absence of respiration. These results have important implications in the energy-linked modifications of tumour radiation response using glucose analogs.