Background: p38 MAPK participates in gases-induced apoptosis signal transmission though it hasn’t molecular structure necessary for interaction with gaseotransmitters.Methodology: annexin positive cells and cells with decreased mitochondrial transmembrane potential were detected by flow cytometry. Caspase 3 and 9 activity was investigated via spectrophotometry. Protein contents of Bcl-2 family members were measured with western blot analysis.Results: Caspase-3 and -9 activity and the number of cells with decreased mitochondrial membrane potential showed the apoptotic reaction vector when p38 MAPK-dependent pathways of NO and CO action inhibited. Inhibition of p38 kinase in H2S treated cells led to caspase-3 activation accompanied with the decrease of the number of apoptotic cells. Proteins Bcl-2 and Bad were the p38 MAPK-dependent targets of all three gases action. P38 MAPK influenced on protein Aven when intracellular H2S concentration increased and on Bcl-xl protein in CO-treated cells. In both cases p38 kinase was the negative regulator of these proteins and promoted the proapoptotic action of gases abolishing the gases-mediated increase of the Aven and Bcl-xl content. Conclusion: p38 MAPK acted proapoptotically in the cases of intracellular increase of NO and H2S and antiapoptotically in CO-treated cells.
