text: The effects of oxidative stress on in vivo brain GSH turnover in young and mature mice.
  Glutathione (GSH) synthetase activities and GSH turnover rates were examined during severe oxidative stress in the mouse brain as induced by t-butylhydroperoxide (t-BuOOH). Brain GSH synthetase activities in 8-mo-old mice in the cortex, striatum, thalamus, hippocampus, midbrain, and cerebellum were found to increase following t-BuOOH treatment. The effect of GSH synthesis on brain GSH turnover rates for 2- and 8-mo-old mice were determined after intracerebroventricular (icv) injection of [35S]cysteine. Rate constants for GSH turnover were determined by least-squares iterative minimization from the specific activity data from 20 min to 108 h after [35S]cysteine administration. GSH and glutathione disulfide (GSSG) specific activities were determined after separation by high-pressure liquid chromatography (HPLC). The half-life of GSH in the 2-mo-old mouse was 59.5 h and in the 8-mo-old mouse was 79.1 h. In summary, defense mechanisms against oxidative stress in the brain differ with age. Young mice can increase the cellular availability of GSH, whereas mature mice can increase GSH synthetase activity during oxidative stress. These differences make mature mice more susceptible to brain oxidative damage.
  
entities.text: ['brain']
entities.type: Organ
entities.entity_id: PMID-9165485_T1
entities.text: ['brain']
entities.type: Organ
entities.entity_id: PMID-9165485_T2
entities.text: ['Brain']
entities.type: Organ
entities.entity_id: PMID-9165485_T3
entities.text: ['cortex']
entities.type: Multi-tissue_structure
entities.entity_id: PMID-9165485_T4
entities.text: ['striatum']
entities.type: Multi-tissue_structure
entities.entity_id: PMID-9165485_T5
entities.text: ['thalamus']
entities.type: Multi-tissue_structure
entities.entity_id: PMID-9165485_T6
entities.text: ['hippocampus']
entities.type: Multi-tissue_structure
entities.entity_id: PMID-9165485_T7
entities.text: ['midbrain']
entities.type: Multi-tissue_structure
entities.entity_id: PMID-9165485_T8
entities.text: ['cerebellum']
entities.type: Multi-tissue_structure
entities.entity_id: PMID-9165485_T9
entities.text: ['brain']
entities.type: Organ
entities.entity_id: PMID-9165485_T10
entities.text: ['brain']
entities.type: Organ
entities.entity_id: PMID-9165485_T11
entities.text: ['cellular']
entities.type: Cell
entities.entity_id: PMID-9165485_T12
entities.text: ['brain']
entities.type: Organ
entities.entity_id: PMID-9165485_T13