Further Experiments on the Fate of Taurine in Dogs.

Abstract

Experiments which were carried out in this laboratory by Schmidt and his co-workers^1,2 showed that when taurine is ingested by man there is no marked increase in urinary sulfates. The α-amino nitrogen determinations in the urine indicated that contrary to the claims of Salkowski, taurine is excreted free and not as taurocarbamic acid. Schmidt and Clark 3 were able to show that the fate of taurine in dogs is the same as in man.

The experiments described below were undertaken with the view of isolating taurine from the urine of dogs which had been fed this substance. For the isolation of taurine we used a modification of the method described by Bergell. 4 The Bergell technique in our hands did not yield positive results. The procedure was as follows: One gm. taurine was dissolved in 100 cc. of urine. To this solution were added 2.5 gm. β-Naphthalene-sulfochloride, in 15 cc. ether, and 9 cc. N-NaOH. After shaking for 2 hours, 1 gm. of the chloride in 10 cc. ether, and 10 cc. N-NaOH were added. The shaking was continued for 8 more hours, care being taken that the reaction remained alkaline throughout the experiment. After completion of the reaction, the aqueous layer was separated and acidified with dilute HCl. A fine sediment separated out. The mixture was placed in the ice-chest over night. The next morning, it was centrifuged and just enough sodium chloride added, until the Na-salt of β-Naphthalene-sulfotaurine began to form. After standing in the ice-chest for 24 hours, the precipitate was filtered, dried and weighed. The substance was purified by recrystallization from 85% alcohol. By this method we were able to recover 0.8 gm. from 1.0 gm. taurine added to 100 cc. of urine.