三乙酰莽草酸对局灶性脑缺血后脑组织损伤和血液流变学的作用

Effects of triacetylshikimic acid on brain damage and blood rheology after focal cerebral ischemia in rats

目的 研究三乙酰莽草酸 (TSA)对局灶性脑缺血后脑组织损伤保护作用及对血液流变学变化的影响。方法 线栓塞法阻断大脑中动脉造成大鼠局灶性脑缺血。TTC染色法测定脑梗死范围。测定脑缺血 2 4h后红细胞变形和集聚能力、全血和血浆粘度。结果 脑缺血 2 4h后 ,脑梗死范围达前脑的 ( 16 .6± 3 .6 ) % ,对侧半球的 ( 32 .0± 8.9) %。脑缺血后立即和 6 0min 2次灌胃给TSA 2 5 ,5 0和 10 0mg·kg- 1 ,可使脑梗死范围 (按占对侧半球的百分比 )分别减少 9.6 % ,2 1.7% (P <0 .0 1)和 31.9% (P <0 .0 1)。TSA 5 0和 10 0mg·kg- 1 还可降低大鼠的神经功能行为评分。尼莫地平 5mg·kg- 1 也可减少脑梗死范围 ,降低神经功能行为评分。脑缺血 2 4h后红细胞变形能力下降 ,红细胞聚集程度、血粘度及血浆粘度皆明显提高。TSA 10 0mg·kg- 1 可明显降低红细胞聚集程度 ,但对红细胞变形和血粘度及血浆粘度无显著影响。尼莫地平可降低切变率为 2 0 0～ 1s- 1 范围内的全血粘度及血浆粘度。

OBJECTIVE To investigate the therapeutic effects of triacetylshikimic acid (TSA) on brain damage and blood rheological changes induced by focal cerebral ischemia.METHODS Focal cerebral ischemia in rats was induced by inserting a monofilament suture into internal carotid artery to block the origin of middle cerebral artery.Infarct size was evaluated by TTC staining.Blood rheological parameters (erythrocyte deformability and aggregation,blood viscosity) were determined 24 h after focal cerebral ischemia.RESULTS Infarct size of the brain was (16.6±3.6)% of total forebrain and (32.0± 8.9 )% of contralateral hemisphere 24 h after focal cerebral ischemia.TSA 25,50 and 100 mg·kg -1 ,given orally immediately and 60 min again after the onset of ischemia,decreased the infarct size (percent of contralateral) by 9.6%,21.7% (P<0.01) and 31.9%(P<0.01),respectively.The neurological deficit scores were decreased by TSA 50～100 mg·kg -1 .Nimodipine 5 mg·kg -1 was also shown to reduce infarct size and neurological deficit scores.Focal cerebral ischemia for 24 h induced a significant decrease in erythrocyte deformabilitym,an increase in erythrocyte aggregation and blood viscosity.TSA 100 mg·kg -1 decreased the erythrocyte aggregation without significant effects on erythrocyte deformability and blood viscosity.CONCLUSION TSA has protective effects on brain damage induced by focal cerebral ischemia.