Treatment method with cell permeable cAMP analog prevents nerve growth element withdrawal induced chromatin condensation of intact rat superior cervical ganglion neurons Neame et al 1998 and protects PC12 cells from proteasome inhibitor induced apoptosis Rideout et al 2001 . The mechanisms accountable for the protective action of cAMP towards apoptosis include the synthesis of antiapoptotic proteins, the inactivation of proapoptotic proteins, and phosphatidylinositol three kinase dependent Akt activation. Although it is reported that a cell permeable cAMP analog also protects cells from 6 OHDA toxicity Yamada et al 1997 , its mechanism just isn’t clear. Serine threonine kinase Akt serves like a multifunctional regulator of apoptotic cell death and cell development.With respect to neuronal cell perform, Akt continues to be shown to be required for your prevention of apoptosis as well as promotion of cell survival by the phosphorylation of proapoptotic Awful Datta et al 1997 and procaspase 9 Cardone et al 1998 . Just lately, it has also been reported that p38 MAPK is induced from the 6 OHDA induced apoptosis Choi et al 2004 .
To get a better insight into the molecular mechanism of neuronal cell apoptosis induced by dopamine metabolites, we investigated the mechanism of six OHDA induced apoptosis of PC12 cells and its protection promoted by cAMP and antioxidants. On this report, we described that 6 OHDA elevated the intracellular superoxide production and induced caspase activation, Bid cleavage, mitochondrial membrane depolarization and chromatin proton pump antagonist condensation, which had been independent of MPT in PC12 cells, and that cAMP suppressed the apoptosis via the restoration of the phospho Akt ranges along with the inhibition of p38 phosphorylation with out the inhibition of superoxide generation and mitochondrial membrane depolarization. 2. Success . six OHDA induced apoptosis of PC12 cells 6 OHDA induced the chromatin condensation of PC12 cells, since it was observed by Hoechst staining Inhibitor 1A . The chromatin condensation depended for the incubation time and 6 OHDA concentration Inhibitor 1B . At 50 M of six OHDA, obvious chromatin condensation was observed from four h and reached a greatest at 12h.
The chromatin condensation was suppressed from the pretreatment with z VAD fmk, which was a universal caspase inhibitor inside a concentrationdependent manner, which indicates MS-275 HDAC inhibitor the involvement on the caspase cascade inside the apoptosis Inhibitor 1C six OHDA activated caspases Caspases are execution proteases of apoptosis induced by numerous stimuli. For the reason that z VAD fmk inhibited six OHDAinduced chromatin condensation, we examined the result of six OHDA on the actions of many caspases implementing specified synthetic substrates for each enzyme. 6 OHDA enhanced the pursuits of caspase 3, eight and 9 in PC12 cells in a time and concentration dependent method Figs. 2A and B .