Figure 1. Irradiation of melanoma cells generates PAF-R agonists.

B16F10 cells were sham-irradiated (e.g. unirradiated) or exposed to ionizing radiation (IR; radiation therapy [RT]). A, B. Examples of intracellular Ca²⁺ mobilization responses in B16F10 cells that were exposed to 5 Gy IR. After 1h, lipids were extracted and PAF-R agonistic activities were measured with Ca²⁺ mobilization responses in FURA-2-labelled PAF-R-expressing KBP (A) or PAF-R-negative KBM (B) cells. KBM cells treated with 1μM endothelin 1 (ET-1) served as positive control. C. Dose-responsiveness of IR-induced PAF-R agonistic activity. B16F10 cells were treated with various IR doses and harvested 1h post-radiation. D. Time course of IR-generated PAF-R agonistic activity. B16F10 cells were irradiated with 10Gy and harvested at various times. Data are mean±SE and expressed as % maximum (1 μM CPAF) intracellular Ca²⁺ response in KBP cells from at least three separate experiments.