脑钠素对大鼠缺血性脑水肿的影响

用电凝法阻断一侧大鼠大脑中动脉（ＭＣＡ），造成缺血性脑水肿模型，用以观察外周（ｉｖ）和中枢（ｉｃｖ）给予脑钠素（ＢＮＰ）对脑水肿的影响。实验结果表明：生理盐水对照组缺血侧脑组织水、钠含量明显升高，钾含量降低，与对侧比较均有显著性差异；ｉｖ给予ＢＮＰ缺血侧脑组织水、钠含量恢复正常，与对侧比较无显著性差异，而钾含量仍然较低；ｉｃｖ给予ＢＮＰ缺血侧脑组织水、钠含量虽未恢复正常，但仍明显降低，而钾含量恢复正常。可以认为无论外周或中枢给予ＢＮＰ，对于减轻或缓解脑水肿均有确切效果，且脑内ＢＮＰ的作用机制与外周不同。

Effect of Brain Natriuretic Peptide on Rat Ischemic Brain Edema:Changes in Brain Water and Electrolytes

It have examined the effects of intravenous (iv) infusion or intraventricular(icv)injection of brain natriuretic peptide(BNP)on the brain water,sodium and potassium contents in rat ischemic brain edema produced by right meddle cerebral artery(MCA)occlusion.In the group treated with iv infusion of 0.9% NaCl,the water and sodium contents in the right cerebral cortex(ischemic region)increased significantly compared with that in the left(nonischemic region).In the group treated with iv infusion of BNP,however,there is no significant difference between left and right in brain water and sodium contents. No effect of iv BNP infusion on the decrease of potassium content was observed.Although the water content in the right cerebralcortex(ischemic region)increased significantly compared with that in the left(non-ischemic region)in both of the groups treated with NaCl and BNP by icv injection,a significant difference in brain water content in the right cerebral cortex was observed.between NS and BNP groups.Icv injection of BNP inhibited significantly the increase of sodium content in the right ischemic region.The decrease of potassium content in the right ischemic region was not observed in the group of icv infection of BNP.The results show that BNP given by iv or icv reduced brain edema and inhibited the increase of sodium content in ischemic region.Icv injection of BNP inhibited the decrease of potassium content in ischemic region,but iv infusion of BNP didn't.It is convinced that BNP is involved in the regulation of systemic fluid and electrolyte balance in the peripheral and central nervous system.The effects of BNP on brain potassium in peripheral and central nervous system may be mediated by different mechanism.