Article

Protective effect of tetraethyl pyrazine against focal cerebral ischemia/reperfusion injury in rats: Therapeutic time window and its mechanism

Department of Rehabilitation, Huashan Hospital, and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200040, China.
Thrombosis Research (Impact Factor: 2.43). 02/2009; 123(5):727-30. DOI: 10.1016/j.thromres.2008.11.004
Source: PubMed

ABSTRACT Tetramethyl pyrazine has been considered an effective agent in treating neurons ischemia/reperfusion injury, but the mechanism of its therapeutic effect remains unclear. This study was to explore the therapeutic time window and mechanism of tetramethyl pyrazine on temporary focal cerebral ischemia/reperfusion injury.
Middle cerebral artery occlusion was conducted in male Sprague-Dawley rats and 20 mg/kg of tetramethyl pyrazine was intraperitoneally injected at different time points. At 72 h after reperfusion, all animals' neurologic deficit scores were evaluated. Cerebrums were removed and cerebral infarction volume was measured. The expression of thioredoxin and thioredoxin reductase mRNA was determined at 6 and 24 h after reperfusion.
Cerebral infarction volume and neurological deficit scores were significantly decreased in the group with tetramethyl pyrazine treatment. The expression of thioredoxin-1/thioredoxin-2 and thioredoxin reductase-1/thioredoxin reductase-2 was significantly decreased in rats with ischemia/reperfusion injury, while it was increased by tetramethyl pyrazine administration.
Treatment with tetramethyl pyrazine, within 4 h after reperfusion, protects the brain from ischemic reperfusion injury in rats. The neuroprotective mechanism of tetramethyl pyrazine treatment is, in part, mediated through the upregulation of thioredoxin transcription.

0 Followers
 · 
299 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Thrombolytic agent is increasingly being used in treating acute ischemic stroke. A novel protease with strong thrombolytic activity, Neanthes japonica (Iznka) fibrinolytic enzyme (NJF) discovered in our laboratory has been reported with characteristics of direct hydrolyzing fibrin and fibrinogen. The neuroprotective effect of NJF and urokinase (UK) was tested in rat models of middle cerebral artery occlusion (MCAO). The model was successfully produced by introducing an intraluminal suture into the left middle cerebral artery (MCA). NJF (0.25, 0.5, 1mg/kg) was injected intravenously 1h after the onset of reperfusion. Compared with vehicle group, MCAO animals treated with NJF showed dose dependent reduction in cerebral infarction with improved neurological outcome. Meanwhile, ischemia induced cerebral edema was reduced in a dose dependent manner. Treatment with NJF at 0.5mg/kg was almost equivalent to UK at 15,000U/kg dosage in the reduction of cerebral infarction and cerebral edema. Biomedical assay showed that NJF treatment suppressed lipid peroxidation and restored superoxide dismutase (SOD) activities in brain tissue. These results suggest that NJF posses neuroprotective potential in rat MCAO and reperfusion model. Neuroprotection shown by NJF may be attributed to inhibition of lipid peroxidation, increase in endogenous antioxidant defense enzymes.
    Neuroscience Letters 02/2011; 489(1):16-9. DOI:10.1016/j.neulet.2010.11.057 · 2.06 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: We previously reported that no distinct neuronal loss occurred in the aged dog spinal cord, although oxidative stress was increased in the aged dog spinal cord. Thioredoxin 2 (Trx2)/peroxiredoxin 3 (Prx3) redox system is a major route for removing H(2)O(2) in the central nervous system. In the present study, we compared the distribution and immunoreactivity of thioredoxin reductase 2 (TrxR2), Trx2 and Prx3 and their protein levels in the spinal cord and hippocampus between the adult (2-3 years) and aged (10-12 years) dogs. The number of TrxR2-immunoreactive neurons was slightly increased; however, its immunoreactivity was significantly increased in the aged spinal cord compared to that in the adult spinal cord. On the other hand, the number and immunoreactivity of both Trx2- and Prx3-immunoreactive neurons were significantly increased in the spinal cord of the aged dog. Similarly, in the hippocampus of the aged dog, TrxR2, Trx2 and Prx3 immunoreactivity and protein levels were markedly increased compared to those in the adult dog. These results indicate that the increases of TrxR2, Trx2 and Prx3 immunoreactivity and their protein levels in the aged spinal cord and hippocampus may contribute to reducing neuronal damage against oxidative stresses during normal aging.
    Experimental gerontology 08/2011; 46(11):946-52. DOI:10.1016/j.exger.2011.08.004 · 3.53 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The dipeptidyl peptidase (DPP) family members, including DPP-IV, DPP8, DPP9 and others, cleave the peptide bond after the penultimate proline residue and are drug target rich. The dimerization of DPP-IV is required for its activity. A propeller loop located at the dimer interface is highly conserved within the family. Here we carried out site-directed mutagenesis on the loop of DPPIV and identified several residues important for dimer formation and enzymatic activity. Interestingly, the corresponding residues on DPP9 have a different impact whereby the mutations decrease activity without changing dimerization. Thus the propeller loop seems to play a varying role in different DPPs.
    FEBS letters 11/2011; 585(21):3409-14. DOI:10.1016/j.febslet.2011.10.009 · 3.34 Impact Factor
Show more