Abstract
Effects of paeonol, a major component of the root bark of Paeonia suffruticosa, on urinary excretion of water (UV), sodium (UNaV), potassium (UKV), chloride (UclV) and osmolality (UosmV) were investigated in bicarbonate saline loaded rats. Paeonol at the doses of 62.5 to 250 mg/kg p.o. produced dose-dependent increases in UV, UNaV and UClV (P < 0.05 or 0.01 vs. control). UKV was unchanged at the lower doses and decreased at the highest dose. UosmV was also increased by paeonol (P < 0.05 or 0.01). The lowest effective dose of paeonol in diuretic action was 62.5 mg/kg which is somewhat lower than those reported to produce an antiinflammatory action or a reduction of gastric secretion (125 to 500 mg/kg). The highest dose of paeonol produced the same degree of increase in UV as hydrochlorothiazide (HTZ) (10 mg/kg), while the increases in electrolytes excretion by HTZ were significantly greater than by paeonol. These data demonstrate that paeonol has a diuretic action, and suggest that its sites of action in the kidney are different from those of HTZ.
