• antioxidative system;
  • lipid peroxidation;
  • room temperature tryptophan phosphorescence (RTTP);
  • viability;
  • Chinese hamster fibroblasts

A method based on the measurement at room temperature of tryptophan phosphorescence (RTTP) gives the unique possibility to investigate the dynamic structure of membrane proteins without their isolation from cells. This method was used to study the influence of tert- butyl hydroperoxide (t -BHP) on Chinese hamster fibroblasts. The treatment of fibroblasts with t -BHP in a concentration range of 0.5–2m m for 60min caused an increase of frequency and amplitude of membrane protein motions with lifetimes of hundreds miliseconds (a decrease of RTTP τ2). In parallel, cell viability was studied by trypan blue exclusion test and the content of thiobarbituric acid reactive substances was measured in cells. The dependences of the RTTP τ2and cell viability on t -BHP concentration were similar. Contrary to this, t -BHP did not induce the activation of lipid peroxidation processes in cells. This indicates that cell death is connected with the excessive increase of intramolecular dynamics of membrane proteins during t -BHP action.