The fate of indolethylamine in the organism / by A.J. Ewins and P.P. Laidlaw.

  • Ewins, Arthur James.
Date:
1913
Catalogue details

Licence: In copyright

Credit: The fate of indolethylamine in the organism / by A.J. Ewins and P.P. Laidlaw. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    Experiment. 025 grm. indolethylamine hydrochloride was perfused through a rabbit’s liver for 2'5 hours. Perfusion fluid and washings were worked up as described above when 50 mgm. of indoleacetic acid were obtained. Yield 44 °/0 of theoretical. The identification was completed by comparison of colour reactions, melting point, and mixed melting point with synthetic /3-indole-pr-3-aceric acid. There can be no doubt then that indolethylamine is readily converted by the liver into indoleacetic acid, just as ^-hydroxyphenylethylamine is converted into p-hydroxyphenylacetic acid. Feeding Experiments. One half to one gram of the hydrochloride of indolethylamine is well borne by a 7-8 kilo dog. Larger doses are inadmissible for our purpose since vomiting and sometimes purgation ensue. The urine of the 36 hours following the administration did not give the colour reactions which we have always found in our perfusion experiments, but on adding to a small quantity of urine half its volume of strong hydrochloric acid and a trace of nitric acid and gently warming, a fine purple colour develops, which gradually (unless the mixture is cooled) becomes deep red and then orange and ultimately yellow. The colour reminds one of a very intense indican reaction. It is not, however, due to the development of indigo since at no stage can a blue component be extracted by chloroform. We found that the chromogen of this colour reaction was an acid, which could be shaken out from the strongly acidified urine with ether or ethyl acetate, but the complete extraction of the chromogen by either of these solvents from acid urine was found to be almost impossible. The acid, however, was found to be much more readily extracted if its solubility in urine was depressed by saturation with ammonium sulphate. In a few experiments with rabbits’ urine this preliminary saturation with ammonium sulphate was found to be of considerable assistance, since the procedure caused a large proportion of the hippuric acid to crystallise [cf. Roaf, 1908]. The ether or ethyl acetate extracts were carefully collected, and washed with ammonium sulphate, and then with a small quantity of water. The acid was then extracted from the ether by sodium carbonate solution. The alkaline extract was acidified, saturated with ammonium sulphate and shaken out with ether. The ether extracts were washed with water and taken to dryness. A thick gum resulted from which nothing would crystallise. The gum was