钩藤总碱抗实验性脑缺血的作用

Effects of Rhynchophylla total alkaloids on experimental cerebral ischemia

目的 观察钩藤总碱 (Rhynchophyllatotalalkaloids,RTA )对脑缺血损伤的影响并对其作用机制作初步探讨。方法 采用小鼠断头张口喘气模型 ,大鼠大脑中动脉缺血 2h/再灌注 2 2h模型 ,神经病学评分 ,脑梗死范围及脑组织水含量变化 ,观察对脑缺血 /再灌注损伤的影响 ;通过测定大鼠脑组织中一氧化氮合酶 (nitricoxidesynthase,NOS)、超氧化物歧化酶 (superoxidedisumtase ,SOD)活性及丙二醛 (malon dialdehyde ,MDA)含量的变化 ,并经原位末端标记法观察对脑细胞凋亡的影响以探讨药物作用的机制。结果 RTA可延长小鼠张口喘气时间 ,降低大鼠脑缺血 /再灌注后神经病学评分及梗死范围 ,降低脑组织MDA、NOS含量及升高SOD活性 ,RTA还能减少神经细胞的凋亡。结论 RTA对脑缺血 /再灌注损伤有保护作用 ,其作用与抑制NOS活性 ,提高SOD活性 ,减少神经细胞脂质过氧化损伤和抑制神经细胞凋亡有关。

Aim To study the protective effects of Rhynchophyll a of total alkaloids ( RTA ) on cerebral ischemia/reperfusion injury and the possi ble mechanism of action. Methods The effects of RTA on decapit ated gasping model and model of middle cerebral artery ischemia 2 h/reperfusion 22 h were observed. The neurological scores, cerebral infarct volume and cerebr al water content after ischemia/reperfusion were observed in rats respectively. The activities of NOS and SOD and the content of MDA in rat's brain tissue were measured. Neuron apoptosis in ischemia penumbral area were detected by terminal depoxynucleotidyl transferase mediated dUTP-biotin nick end labeling ( TUNEL ) . Results The average gasping times in mice treated with RTA 50 , 75 mg·kg -1 was significantly prolonged. The cerebral infarct volume and cerebral water content in rats treated with RTA 40, 60 mg·kg -1 were sign ificantly decreased in ischemic rats. RTA 40, 60 mg·kg -1 increased the ac tivity of SOD ,and decreased the activity of NOS and the content of MDA in the i schemic brains of rats. The number of apoptotic neurons in ischemia penumbral ar ea of cerebral tissue of rats treated with RTA 40, 60 mg·kg -1 was signif icantly lower than that in control rats. Conclusions RTA has pr otective effect on cerebral ischemia/reperfusion injury; this may be related to inhibit the activity of NOS and lipoperoxidation, and increasing the activity of SOD and decreasing neuron apoptosis.