Ascorbate-mediated cell death was due to protein-dependent
extracellular H2O2 generation, via ascorbate radical formation from ascorbate as the electron donor. Like glucose, when ascorbate is infused
i.v., the resulting pharmacologic concentrations should distribute rapidly in the extracellular water space (42). We showed that such pharmacologic ascorbate concentrations in media, as a surrogate for extracellular fluid, generated
ascorbate radical and H2O2. In contrast, the same pharmacologic ascorbate concentrations in whole blood generated little detectable ascorbate radical
and no detectable H2O2. These findings can be accounted for by efficient and redundant H2O2 catabolic pathways in whole blood (e.g., catalase and glutathione peroxidase) relative to those in media or extracellular
fluid
Nathan Goodyear on 11 Mar 14rat model finds that progesterone effects internal cell enzyme activity. In this case, progesterone increased PP2A in the cerebellum and in the hyippocampus. Interesting, that E2 priming decreased the effects on the hippocampus, but not the cerebellum. This reveals a biochemical link between sex hormones, progesterone in this case, and the brain. Studies have shown progesterone to be neuroprotective in TBI. This may be one mechanism.
