Fig. 5

Oxycodone differentially induces pro-and anti-apoptotic signaling in cell bodies and axons. a Immunohistochemical analysis of phospho-eIF2α, ATF4, Bax, cleaved caspase 3 (Casp3), XIAP, and NF in striatum of rats treated with water (W) or oxycodone (O). Arrows point to axonal fascicles. Scale bar denotes 20 μm for all images. b Graphs of the densitometric analysis of phospho-eIF2α, ATF4, Bax, cleaved caspase 3 (Casp3), XIAP, and NF staining in bundles of the striatum rats treated with water (open bars) or oxycodone (grey filled bars). The graphs represent relative density measured as the ratio of the mean values of intensities obtained from oxycodone exposed tissue to the bundle intensities in striatum of water-exposed rat brains set as 1 (± SEM). Data obtained from three animals for each treatment. Statistical analysis was performed using Student’s t-test. eIF2α-P, p < 0.001; ATF4, p < 0.001; Bax, p < 0.001; cleaved caspase 3, p < 0.001; XIAP, p < 0.001; and NF, p = 0.3. c Graphs of the densitometric analysis of phospho-eIF2α, ATF4, Bax, cleaved caspase 3 (Casp3), XIAP, and NF staining in cell bodies in striatum of rats treated with water (open bars) or oxycodone (grey filled bars). Data presented as a percent of positively stained cells relative to total number of cells. Data obtained from three animals for each treatment, Data expressed as mean value (± SEM). Statistical analysis of positively stained cells in oxycodone relative to water exposed striatum was performed using Student’s t-test. Phospho-eIF2α, p < 0.001; ATF4, p = 0.2; Bax, p < 0.05; and XIAP, p < 0.01. d Western blot analysis of XIAP and phospho(Thr181)-Tau in rat cortex lysates. Left panel, the representative images of western blots of XIAP, phospho-Tau, total Tau, actin and GAPDH in cortex of rats treated with water (W) or oxycodone (O). Right panel, graphs of the densitometric analysis of XIAP and phospho-Tau western blots. The graphs represent the mean ratio of signal of XIAP to actin and phospho-Tau to total Tau. Oxycodone data were normalized to water samples in corresponding tissues set as 1 (± SEM). XIAP, n = 3, p < 0.05; P-Tau, n = 4, p < 0.003. Open bars—XIAP; and grey filled bars—P-Tau