Figure 4.

Cytokine concentration in cell culture medium. Cells were irradiated 2 Gy and subsequently incubated in 1g or µg. After 24 h cytokine concentration was measured. Radiation induced cytokine production in µg but not in 1g. Isoproterenol treatment prior to radiation prevented the production of all cytokines. Bars represent mean + 1 SEM from 10 independent experiments. The synergistic effect of isoproterenol and radiation in µg (Iso × R(µg)) was significant for all four cytokines. Statistical analyses are summarized in Table 4 and Table 5.