Changes in the urinary constituents in rats with chronic renal failure during oral administration of rhubarb extract.

The effect of rhubarb extract on the urinary constituents was examined in rats with chronic renal failure induced by adenine. Orally administered rhubarb extract caused a significant decrease in the urinary excretion of urea. The amount of urinary Na, K, and Ca was significantly reduced in the rhubarb extract-treated rats, while urinary inorganic phosphate was significantly elevated. A polyuria-preventive effect was observed. However, there was no marked change in the amount of urinary creatinine throughout the experimental period. The mechanism of uremia-improving action of rhubarb extract is discussed on the basis of the present results and the previously reported data [Chem. Pharm. Bull., 32, 4506 (1984)].