黄芪水提物对健康人尿钠排泄的影响及机制研究

Effect of aqueous extract of Astragali radix on urinary sodium excretion in healthy men

目的 探讨黄芪水提物（ARE）对健康人的利尿利钠作用及其机制。方法 采用双盲交叉试验。12名健康男性志愿者口服生理盐水（10ml／kg）后随机分为ARE组和安慰剂组，2周洗脱期后再进行试验。结果 与安慰剂组相比，ARE组尿钠排泄量（UNaV）在1．5h和2h分别增加73％和43％，2h时达高峰[（0．30±0．05）比（0．21±0．02）mmol／min，P〈0．05]，4h时作用基本消失。尿钠排泄分数（FENa）和尿氯排泄量（UαV）也显著增加，均在2h达高峰，而尿量、尿钾及尿肌酐排泄量在服药4h内均无增加，12h和24h尿量及尿电解质排泄量也无改变。口服ARE后血浆心钠素浓度（pANP）、尿环磷酸鸟苷排泄量（UcGMPPV）及UcGMP V／pANP比值均在2h显著增加（P〈0．05）。U Na V与血浆pANP、UcGMPV及UcGMPV／pANP比值正相关（P均〈0．05），而与Ccr无相关（r=0．153，P〉0．05）。结论 ARE能增加健康人尿钠排泄，其机制与ARE促进ANP产生以及增加ANP肾脏活性有关。

Objective To evaluate the diuretic and natriuretic effect of aqueous extract of Astragali radix （ARE） and explore its possible mechanism. Methods Twelve healthy men were randomized to receive either placebo （n = 6） or a single oral dose of 0.3 g/kg body weight of ARE （n = 6） in a double-blind manner before oral administration of 10 ml/kg of 0.9% saline load. After two-week washout period, the subjects were crossed over. Results Compared with placebo, ARE produced significant increments in urinary sodium excretion （UNaV） which reached a peak at 2 h [（0.30±0.05） vs （0.21±0.02） mmol/min, P 〈 0.05], as well as fractional sodium excretion, urinary excretion of chloride during 4 hours but none in urine volume, urinary potassium and creatinine excretion. No significant changes were observed in urine volume and urinary excretion of sodium, chloride and potassium during 12 hours and 24 hours. ARE also elevated plasma atrial natriuretic peptide level （pANP）, urinary excretion of cGMP （UcGMPV） and UcGMPV/pANP ratio without affecting plasma renin-angiotensin-aldosterone system （RAAS）, mean arterial blood pressure and creatinine clearance rate （Ccr）. UNaV was positively correlated with pANP, UcGMPV and UcGMPV/pANP ratio （r = 0.947,0.957,0.442, all P 〈 0.05）, but not correlated with Ccr （r = 0.153, P 〉 0.05）. Conclusions ARE induces obvious natriuresis in healthy men and the effect is at least partly attributed to an increase in ANP secretion and its renal responsiveness.