下丘脑损伤与血钠紊乱的动物实验研究

Experimental study on lesion of the hypothalamus and disorders of serum sodium

目的探讨下丘脑损伤与血钠紊乱的关系及血浆脑钠尿肽(BNP)在血钠紊乱发生中的作用.方法采用立体定位电解毁损大鼠下丘脑不同区域复制下丘脑损伤的动物模型,检测血钠、尿钠及血浆BNP含量,记录饮水量和尿量,计算水平衡.结果下丘脑前部毁损组术后1～3d血钠均较术前显著升高,下丘脑后部毁损组术后2d血钠较术前显著降低;下丘脑后部毁损组术后1d血浆BNP含量较术前及术后3d显著升高.术后1d下丘脑后部毁损组血浆BNP含量较其它组显著升高.结论下丘脑前部损伤引起高血钠,下丘脑后部损伤导致低血钠.下丘脑后部毁损组血钠降低伴有血浆中BNP含量升高,提示血浆BNP含量的升高可能是下丘脑损伤致低血钠的原因之一.

Objective To analyze the relationship between lesion of the hypothalamus and disorders of serum sodium and to investigate the role of brain natriuretic peptide(BNP) in the disorders of serum sodium. Methods By using a stereotaxic instrument, the rat model of hypothalamic lesions was made by a direct current. Three groups were studied (n=8): (1)sham group, (2)anterior hypothalamus lesion group, and (3)posterior hypothalamus lesion group. Water intake and urinary volume were recorded daily. Serum sodium, sodium excretion and plasma BNP concentration were measured. Results In anterior hypothalamus lesion group, serum sodium concentrations on 1d, 2d and 3d after operation were significantly higher than that prior to operation. In posterior hypothalamus lesion group, serum sodium concentration on 2d after operation was obviously lower compared with that prior to operation, and plasma BNP concentration on 1d after operation was much higher than that prior to and on 3d after operation. Conclusions Lesion of anterior part of hypothalamus caused hypernatremia. Lesion of posterior part of hypothalamus led to hyponatremia, accompanied by increased plasma BNP concentration, which suggested that the increase of plasma BNP concentration may play a role in hyponatremia caused by hypothalamus lesion.