Figure 6.

Depletion of TLR4 in vivo ligands impaired basal radio-resistance. (a). C57BL/10 mice (20 g in weight, N=20 per group) pretreated with or without four different gut flora depletion methods (Materials and Method section) and then subjected to 7 Gy IR. The survival was recorded. (b) Commensal gut flora depletion impaired radio-resistance in both C57BL/10 mice and BALB/c mice and attenuates the radio-sensitivity variation between these two strains of mice. (c) Linear regression analysis of the survival rate for commensal-depleted mice and commensal normal control mice after IR. The equation and the correlation coefficient for the line are given. The calculated DRF using these equations was 1.54 (commensal normal mice versus commensal-depleted mice). (d) Reconstitution of commensal gut flora-depleted animals with LPS could partly rescue the severe mortality of commensal gut flora-depleted mice after IR. *P<0.05; NS: No significant difference detected