中藥方劑二金排石湯經臨床上的應用，發現具有治療泌尿道結石之療效，然其藥理作用尚未闡明。故本研究擬針對二金排石湯對實驗性大鼠膀胱結石的影響進行評估。大鼠膀胱經穿線五週後，均可誘發結石之產生。但體重相近，性別不同的大鼠，其誘發結石數量略有差異，雄性多於雌性。二金排石湯於體外實驗中，對膀胱結石具劑量依存性的明顯溶解作用，而且在酸性條件下作用較強。二金排石湯每天口服投與0.1 、0.5 、及1 g/kg ，連續投與21 天，對於誘發大鼠膀胱結石的形成，呈抑制作用；又於大鼠膀胱內的埋石，也具溶解作用，然均無劑量依存性。另外，就體內酸鹼值而言，不論在酸性或鹼性的尿液中，對膀胱內的埋石，均具溶石效果，其作用於酸性尿液中較明顯。長期投與二金排石湯（1~4 週），對於大鼠膀胱內的埋石，不但會抑制其增長，且又具溶解作用，效果與給藥時間成正比。由以上結果顯示，二金排石湯對於實驗性動物膀胱結石，不但能預防結石的產生，更具有溶解結石的作用。The effects of Er-Jin decalculous decoction (EJDD) on the dissolution and the prevention of rat bladder calculi were evaluated. The weight of the bladder calculi which were produced experimentally by inserting surgical silk suture into rat urinary bladder for 5 weeks was about 25 mg/100 g body weight. A marked dissolution of the established bladder calculi was demonstrated in vitro by incubation with EJDD solution at 37 °C, 2 days and was dose-dependent. The dissolution of EJDD was more effective in acidification than in alkalization. EJDD administered orally for 3 weeks attenuated the bladder calculi formation and dissolved the established bladder calculi. These effects revealed markedly both in urinary acidification and urinary alkalization. However, the effects of EJDD on the bladder calculi in the urinary acidification were more effective than in the urinary alkalization. In the long term oral administration (1~4 weeks), EJDD dissolved markedly the established bladder calculi. The intensity of the dissolution was related to the time of administration. From the above results, it indicated that EJDD was effective in both preventing the bladder calculi formation and dissolving the established bladder calculi.