Figure 7.

Astrocytes did not become reactive after radiation exposure. Astrocytes were exposed to X-rays (200 kV, 15 mA) with doses up to 8 Gy (A–C) or to iron ions (D) and fixed for GFAP immunostaining after different time points. (A) Exemplary microscopy images of GFAP (green) immunostaining showing an unirradiated control and cells irradiated with different doses of X-rays at 1 h after radiation exposure. The nucleus was stained with DAPI (blue) for all images. Bar: 50 μm. (B) Dose effect curves of astrocyte reactivity (GFAP) 1 h and 24 h after exposure to X-rays (n = 5). (C) The GFAP fluorescence intensity of astrocytes irradiated with different doses of X-rays over a time course up to 24 h reveals a basal expression of GFAP but no radiation-induced changes. The samples were compared via 2way ANOVA, based on a sample size n = 4 (p < 0.05). (D) Exposure to different doses of ⁵⁶Fe ions (LET 151 keV/μm, 996.5 MeV/n) did not lead to a dose-dependent increase of GFAP expression, but astrocytes showed a basal expression (n = 2). In (B–D) data are shown as mean ± SD. In case that the error bars are smaller than the symbol, they are not visible (D).