组氨酸对光化学诱导的血栓性局部脑缺血的防治效应

Protective effects of histidine on photochemically induced thrombotic cerebral ischemia

用光化学诱导大鼠皮层血栓形成并观察单线态氧清除剂组氨酸对血栓性局部脑缺血的防治效应。结果表明，光化学反应后缺血区皮层磁化率降低（Ｐ＜０．０５）、脑电（ＥＥＧ）抑制、脑水含量由８１．００±０．９５％增加到８５．７８±３．７９％（Ｐ＜０．０１）和全血血小板聚集功能明显增强（Ｐ＜０．０１）。经一次静注组氨酸溶液（５ｍｇ／ｋｇ）治疗的动物，上述各项指标与对侧或对照组比无明显差异（Ｐ＞０．０５）。证明光化学诱导的脑血栓形成与单线态氧形成、血管内皮受损有关。由于组氨酸可清除单线态氧而对脑功能具有保护作用。

Protective effects of histidine,a singlet oxygen scavengers,on regional cer-ebral ischemia caused by the photochemically induced cortex thrombosis were studled inrats. Treated rats received an injection of 5mg/kg histidine at 30 min following photoche-mical reaction. Magnetic suceptability,water content, electroencephalogram (EEG) in corti-cal region and whole blood platelet aggregation were observed before and 4,24 hoursafter photochemical reaction. The results sliowed that magnetic suceptability was markedlydecreased(P<0.05),whole blood platelet aggregation increased(P<0.01)and EEG severlydepressed at 4 hours and brain water content in the ischemic area was increased from81. 00 ± 0.95%to 85.78 ± 3.79%(P<0.01)at 24 hours following cerebral thrombosis. Intats treated with histidine ,significant differences of above indexes were not documentedwithin irradiated area compared with controls(P>0.05).This suggested that brain functionsis damaged most likely by singlet oxygen derived from rose bengal:which was well pro-tected by histidine.