PA and Sn induce RIN cell apoptosis through induction of nitric oxide production. RIN cells were cultivated without treatment (medium) or treated with Sn and/or PA and/or hemoglobin (Hb, 20 mg/ml) and/or SB202109 (40 μM). After 2 or 6 hours RIN cells were fixed before cell-based ELISA for iNOS (A). Cells were stained with DAF-FM (B, D) and AnnV/EtD-III (C) after 6 hours of cultivation. Mean values +/- SD of values obtained in three individual experiments with similar results are presented (A, C). Alternatively, plots from a representative of at least three experiments with similar data are presented (B, D). *p < 0.05 represents a statistically significant difference relative to the cultures grown in medium without additional treatment (A, C) and to the cultures treated with Hb (C).