THE DIURETIC AND HYPOTENSIVE ACTION OF ASTRAGALUS MEMBRANACEUS BGE.

The root of Astragalus membranacesis Bge. is used in Chinese medicine as a cure for chronic renal edema. The present work was conducted to study its diuretic and some other related effects. A dose of 0.5 g/kg was found to have a marked diuretic action either in rats ad- ministered hypodermically or in anaesthetized dogs intravenously. Following oral ad- ministration to normal persons, it also showed a diuretic action. Such an action persisted for 7 days following a hypodermic injection into rats. No tolerance appeared on hypo- dermic injection in rats once daily for 7 days. The diuretic potency seen at 0.5 g/kg was similar to aminophyllin at 0.05 g/kg or hydrochlorothiazide at 0.2 mg/kg. The drug given intravenously or by stomach tube to anaesthetized dogs at 0.5 g/kg produced a remarkable fall of blood pressure. Repeated intravenous injection caused tachyphylaxis. A dose of 75 g/kg orally showed no toxic effect in mice. The LD₅₀ in mice by in- traperitoneal injection had been found to be 40±5g/kg. No side effect in rats was found on chronic toxicity test.