Quenching of Singlet Oxygen by Biomolecules From L1210 Leukemia Cells

Photochem Photobiol. 1992 Apr;55(4):523-8. doi: 10.1111/j.1751-1097.1992.tb04273.x.

Abstract

Singlet oxygen lifetimes for detergent-dispersed L1210 leukemia cells in deuterium oxide buffer were measured by following the decay of 1270 nm phosphorescence. Four photosensitizers and two detergents were studied. Stern-Volmer plots were linear over the cell concentration range studied (0-10(7) cells/mL). The singlet-oxygen quenching constants obtained depended somewhat upon the specific combination of detergent and photosensitizer used. Extrapolation of the singlet-oxygen lifetime data to "100%" cell concentration (1.39 +/- 0.04 x 10(9) cells/mL) and correction for the contribution of the water solvent gave a singlet-oxygen lifetime between 0.17 and 0.32 microseconds for the L1210 leukemia cell. The theoretical contributions of various types of biological molecules within the L1210 cell to the total singlet-oxygen quenching were calculated from their concentrations and their quenching constants. These calculations suggest that proteins will quench most of the singlet-oxygen. Only about 7% of the singlet-oxygen is quenched by water.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Kinetics
  • Leukemia L1210 / metabolism*
  • Luminescence
  • Mice
  • Oxidation-Reduction
  • Oxygen / metabolism*
  • Photochemistry
  • Radiation-Sensitizing Agents
  • Singlet Oxygen
  • Time Factors
  • Tumor Cells, Cultured

Substances

  • Radiation-Sensitizing Agents
  • Singlet Oxygen
  • Oxygen