正、负加速度交替急性大鼠脑组织NO、NOS及血浆ET的含量变化

目的：研究正、负加速度交替暴露后急性大鼠脑组织一氧化氮（NO）、一氧化氮合酶（NOS）及血浆内皮素（ET）的含量变化，探讨正、负加速度交替暴露后，易发生加速度引起意识丧失（G-indnced less of consciousness,G-LOC)的机制。方法：30只雄性Wistar大鼠随机分成3组：对照组、正加速（ Gz）组和正、负加速度（ Gz和-Gz）交替组。于暴露后即翔麻醉采血、取脑。测定脑组织NO、NOS及血浆中ET的含量。结果： Gz组和 Gz、-Gz交替组与对照组比较，脑组织中的NO、NOS及血浆中ET的含量增多，有显著性差异； Gz、-Gz交替组与 Gz组比较，脑组织中的NO、NOS及血浆中ET的含量增多，有差异性。结论： Gz、-Gz交替暴露和单纯 Gz、-Gz暴露均可使脑组织中的NO、NOS及血浆中ET的含量增多；且 Gz、-Gz交替暴露增多明显。说明 Gz、-Gz交替暴露对大脑所致损伤程度更重。

Variation of NO,NOS level of brain tissue and plasma ET in rats induced by positive and negative acceleration

Objective:To investigate the changes of nitric oxide (NO) and nitric oxide synthase(NOS) level of brain tissue and blood plasma endothelin (ET) in Wistar rats immediately after positive and negative acceleration, and explore the mechanism of G-induced less of consciousness(G-LOC). Methods:Thirty rats were divided into 3 groups at random:control group,+Gz group and +Gz --Gz group. The control group was under +1 Gz loads. The +Gz group was under +5 Gz loads and maintained for 40 seconds, then turned to +10 Gz loads for 2 minutes. The +Gz-Gz group was first under +5 Gz loads for 30 seconds, then turned to -5 Gz loads for 5 seconds, and returned to +5 Gz at once, the loads was increased to +10 Gz and lasted for 2 minutes. The growth rate was 1G/s. Repeated for 4 times, the interval was about 5 minutes. Rats were anesthetized immediately to collect blood and brain tissue in order to detect the content of NO, NOS of brain tissue and ET of the plasma. Results:The content of NO,NOS and ET of +Gz group and +Gz--Gz group were increased significantly in comparison with the control, and they were significantly higher in +Gz--Gz group than that in +Gz group. Conclusion: +Gz and +Gz--Gz lead to increase of NO, NOS and ET. +Gz after -Gz repeatedly is more harmful to brain.