Effects of tetramethylpyrazine on cell proliferation in dentate gyrus in rat brain after cerebral ischemia-reperfusion injury

Objective: To observe the effects of tetramethylpyrazine (TMP) on cell proliferation in dentate gyrus (DG) in rat brain after cerebral ischemia-reperfusion injury. Methods: Male SD rats were randomly divided into normal, sham-operation, control and TMP treatment groups. The control and TMP treatment groups were further divided into 5 subgroups. 1 d, 3 d, 7 d, 14 d and 21 d reperfusion after 2 h middle cerebral artery occlusion (MCAO). The focal cerebral ischemia-reperfusion model was made by MCAO. S phase cells were labelled with BrdU. Immunohistochemistry method was conducted to detect the BrdU positive cells. The total number of BrdU positive cells in the DG was measured. Results: There was a significant increase of BrdU positive cells in DG of TMP treatment on 3 d and 7 d groups compared to that in control group (P < 0.05). The total number of BrdU positive cells reached a peak on d 7 and declined afterwards. Conclusion: Tetramethylpyrazine may promote cell proliferation in DG in adult rats after ischemia-reperfusion injury.