Objective: To investigate the mechanisms of Buyang Huanwu Decoction (BYHWD) by observing its effects on expressions of angiopoietin-1 (Ang-1) and the endothelial-specific receptor tyrosine kinase (Tie-2) mRNA in damaged region of rats' brain after intracerebral hemorrhage (ICH).
Methods: One hundred and sixty Sprague-Dawley rats were randomly divided into four groups, 10 in the normal control group, 60 in the sham-operative group, 60 in the ICH model group, and 30 in the BYHWD-treated group. The ICH model was established by injecting collagenase type VII 0.5 U stereotaxically into right globus pallidus. Animals in the BYHWD-treated group were administered orally with BYHWD, while animals in the sham-operative group and the ICH model group were administered orally with equal volume distilled water, and those in the normal control group drank water freely. The positional variations of the expression of Ang-1 and Tie-2 in the sham-operative group and the model group were assayed by immunohistochemistry on dayl, 4, 7, 14, 21 and 28 after modeling, in the meantime, the dynamic changes of Ang-1 and Tie-2 mRNA expressions in all groups were assayed by reverse transcription-polymerase chain reaction (RT-PCR).
Results: No significant expression of Ang-1 and Tie-2 in brain of rats in the normal or the sham-operative group was found during the experiment. In the model group, the Ang-1 and Tie-2 positive micrangio-segments appeared at the edge of clot on day 1 to day 4, they gradually penetrated to hematoma area from day 7; with Ang-1 and Tie-2 mRNA expressed from day 1, but very weak until day 4, showing no significant difference to that on day 1; thereafter, they increased gradually, and reached the peak on day 28 (P <0.05). While the two expressions in the BYHWD treated group reached the peak on day 21, and from day 7 to day 28, they were all significantly higher than those in ICH model group at the corresponding time points (P <0.01).
Conclusion: BYHWD can promote the up-regulation of Ang-1 and Tie-2mRNA expressions in brain of intracerebral hemorrhagic rats, which might accelerate the angiogenesis in the reconstruction of microvascular network in the damaged zone, and thus facilitating the repairing of damaged tissue.