肼跨血脑屏障转运动力学的研究

Study on transport kinetics of hydrazine across blood-brain barrier in rats

目的研究液体火箭推进剂肼跨血脑屏障转运的动力学特征。方法采用原位脑灌流技术对雄性Wistar大鼠进行肼的双侧脑灌流,肼灌流浓度分别为100、200和400μg/ml,灌流时间为2、5、8及10min,取脑,采用对-二甲氨基苯甲醛比色法进行脑组织中的肼浓度测定。结果肼可跨过血脑屏障进入脑实质,脑中肼浓度随着灌流浓度和灌流时间的增加而呈上升趋势;肼在各灌流浓度下跨血脑屏障转运的速度常数Kin分别为0·0126、0·0116和0·0128ml·min-1·g-1,不随灌流浓度的升高而改变。结论肼跨血脑屏障转运属于被动扩散的膜限速模型。

Objective To evaluate the kinetics of hydrazine transport across blood-brain barrier in rats. Methods Sixty Wistar rats served as subjects. In situ bilateral brain perfusion technique was used for hydrazine perfusion to brain. The hydrazine concentration in the perfusate was 100, 200 and 400μg/ml respectively, and the perfusion time was 2,5,8 and 10 rnin respectively. The rats were decapitated at the end of perfusion, and the concentration of bydrazine in the brain parencbyma was measured by p-dimethylaminobenzaldehyde colorimetry. Results Hydrazine can transfer across blood-brain barrier to brain parenchyma. The concentration of hydrazine in brain increased along with the increase of perfusion time and hydrazine concentration in the perfusate. Unidirectional transfer constant （Kin） values of hydrazine at different perfusion concentrations across blood-brain barrier were 0. 0126, 0. 0116 and 0. 0128 ml· min^-1· g^-1 respectively, showing that the values did not change along with the increase of the hydrazine concentration in the perfusate. Conclusions The transport of hydrazine across blood-brain barrier accords with the model of passive diffusion in a membranelimited rate.