The time courses of extracellular H2O2 concentration changes following impact injury to the rat spinal cord in saline-treated, MPSS-treated, and MnTBAP-treated groups. The procedure was described in detail in the Methods section. After three microdialysates were collected at 20-min intervals to establish a basal level, a weight was dropped at time 0 onto the cord (25 g·cm), and sampling was continued for another 5 h at 20-min intervals. A single dose of MnTBAP (4 mg/kg) or the equivalent intrathecal standard regimen of MPSS (bolus dose plus maintenance dose for a total of 9.24 mg/kg as described in the Methods) was administered into the intrathecal space of the cord through a catheter implanted in the terminal cistern. The samples were collected in vials containing a solution of FeCl2 and salicylate. H2O2 in the microdialysates were converted to ● OH in the collecting vials by the Fenton reaction. The ● OH produced in the collecting vials rapidly attacks salicylate to produce 2,3- and 2,5-DHBA. The salicylate hydroxylation products 2,3- and 2,5-DHBA were analyzed by HPLC with electrochemical detection. The 2,3-DHBA was calibrated to the amount of H2O2. Clearly, both MnTBAP and MP reduced H2O2 to its basal level.
Liu et al. BMC Neuroscience 2013 14:23 doi:10.1186/1471-2202-14-23