| Objective:Inspect the dynamic variation of hsp20and bcl-2in brain tissue after cerebral ischemia/reperfusion (I/R) in SD rats, analyze their correlation, explore their effects in cerebral I/R. Investigate the effects of Danhong injection on hsp20and bcl-2after cerebral I/R in rats, clarify the possible mechanism of Danhong injection.Method:Randomly divide60250g-320g healthy SD rats into4groups: normal group (n=10), Sham-operated group (n=10), I/R group (n=20) and Danhong injection treatment group (n=20). Build the cerebral ischemia (2h) and reperfusion model in rats with Longa method. Further divide the I/R group and Danhong injection treatment group into4subgroups (5rats for each subgroup):6hours group (6h),1day group (1d),3days group (3d) and7days group (7d). Evaluate the nervus function coloboma of rats with the Bedersonl5-grades evaluation method. Investigate the pathology variation with HE staining method; Inspect the dynamic variation of the positive cells expression level of hsp20and bcl-2with immunohistoch-emistry; determine the hsp20mRNA expression in samples with the RT-PCR method.Results: 1. HE staining:normal group and Sham-operated group show that there is no obvious focus of infarct in the brain tissue, neuron structure and morphology are normal, no interstitial edema. I/R group shows neurons necrosis, and the lesions side neurons necrosis degeneration phenomenon is elevated and coupled with gliosis with time. And compared with subgroup with the same time point of I/R group, the treatment group shows obvious less brain tissue damage.2. Immunohistochemistry results:(1) hsp20occasionally shows positive cells in normal group and Sham-operated group. No difference between these two groups (P>0.05). The expression of hsp20starts to increase in I/R6h group, reach the summit after3d, and then starts to decrease. The expression mainly locates at neuron hippocampus, glial cell cytoplasm and cerebral vascular endothelial cells. Compared with the Sham-operated group and normal group, I/R group shows significantly (P<0.05) different hsp20expression.(2) Bcl-2occasionally shows positive cells in normal group and Sham-operated group. No difference between these two groups (P>0.05). Bcl-2starts to increase rapidly in I/R6h group, reach the summit after1d, and then starts to decrease with time. Compared with the Sham-operated group, I/R group shows significantly (P<0.05) different bcl-2positive cell number.(3) In Danhong injection treatment group, the hsp20expression time is comparable with I/R group, but the positive cell number is significantly (P<0.05) higher than I/R group.3. RT-PCR investigation results:in I/R group, hsp20mRNA starts to increase in6h, reach the summit after3d, and then starts to decrease, which shows significant (P<0.05) difference from normal group and Sham-operated group, and there is significant difference between each group. The hsp20mRNA expression time in Danhong injection treatment group is comparable with I/R group:starts to increase in6h, reach the summit after3d, and then starts to decrease slowly. However, the hsp20mRNA expression quantity is significantly (P<0.05) higher than I/R group.Conclusions:1.Expressions of hsp20and bcl-2both increase after cerebral I/R.2.Danhong injection will promote the expressions of hsp20and bcl-2, and may have neuroprotection effects. |
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