有機酸鹽による利尿の研究

醋酸-, コルク酸-, アヂピン酸-, コハク酸ソーダの利尿作用と其腎内排泄部位とに就て

抄録

In a recent research sodium succinate has been used as an antidote against pentobarbital-intoxication, and now it is generally accepted that succinate has a remarkable diuretic action. This has promoted considerable interest for us. Including this agent, I have compared the diuretic actions of dicarboxylic acid salts in this series, that is sodium succinate, adipate and suberate while taking acetate as a standard. Japanese toads were used, throughout in this experiment for a study of diuresis. I incised skin and muscles of this animal on its back on a dry wooden board by thermocautery without anesthesia. Special cannula were inserted into the ureters on both sides, and using a Y-form tube the urine was collected into a thin glass measuring cylinder, and its amount was read every 15 minutes. With. no water-supply the urine of the animals tnus treated generally decreased slowly and rather regularly, and 2 or 3 hours later its quantity reached a level of ca. 0.1 cc in this time-interval. Using this level as a control, 0.5-1.0 cc of 1 normal solution or 4 cc of isotonic solutions these agents were injected into Vena cutanea magna. Soon after this injection the urine-flow increased in most cases, and usually after one hour more it returned to the control level; sometimes tp a lower level than before. This increased portion during this period was divided by injected solution's quantity and multiplied by 100, so I expressed the activity of the diuretic action of a certain pharmaca in percent-rate. As to the method for the investigation of the ratio of excreted substances through both glomeruli and tubules, I applied “modified Tamura's operation” on Japanese toads. The determination of the agents in toad's urine was carried out by Van Slyke and Palmer's method well known as the total organic acid estimation of urine, but I modified it slightly in details taking thymol blue as an indicator instead of phenolsulphophthalein and tropaelin 00. Increase of urine flow by the intravenous injection of 1 normal solution of acetate was 50.8%, succinate 82.9%, adipate 79.4% and suberate 132.6%. On the other hand, in case of isotonic solution, acetate was 25.9%, succinate 41.9%, adipate 28.2% and suberate 49.5%. The ratio of elimination of organic sodium salts from tubules as compared with that from glomeruli, by the intravenous injection of acetate was 4/100, succinate 14/100, adipate 17/100 and suberate 25/100. The diuretic actions of these salts were usually less effective When injected into Vena abdominalis which corresponds to the portal vein of warm-blooded and the liverless toads according to Molitor and Pick's method very often showed higher diuretic response to the organic salts than normal toads.