The water-soluble active principles of ergot / by G. barger and H.H. Dale.

  • Barger, George, 1878-1939.
Date:
[1909?]
Catalogue details

Licence: Public Domain Mark

Credit: The water-soluble active principles of ergot / by G. barger and H.H. Dale. Source: Wellcome Collection.

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    Journal Physiology, Vol. XXXVIII. [From the Proceedings of the Physiological Society, May 15, 1909.] The water-soluble active principles of ergot. By G. Barger and H. H. Dale. About two years ago we called attention1 to the fact that certain watery extracts of ergot possess a considerable physiological activity. Injected intravenously such extracts produce a considerable rise of arterial blood pressure, which cannot be attributed wholly to ergotoxine: for these extracts, unless injected in large quantities, do not, as a rule, produce the secondary abolition of the motor effects of sympathetic nerves, shown by us to be characteristic of ergotoxine. Moreover they retain almost all their activity on the blood pressure after treatment which removes what little ergotoxine they contain. Recently, while engaged in investigating the pressor principles produced by putrefaction2 we were struck by the similarity between the action of extracts from putrid meat and that of the preparations of ergot under discussion. This suggested the investigation of the latter by the methods which had proved successful in the case of the former. Since one of the pressor substances produced by putrefaction was shown to be isoamylamine, we submitted an active watery extract of ergot to steam-distillation after making it alkaline. The distillate from 3 kilos of ergot, after suitable purification, finally yielded between 2 and 3 centigrammes of a crystalline oxalate melting at 162° C. Acid isoamylamine-oxalate melts at 169°, and the identity was further made extremely probable by the similarity in crystalline form, and the quantitative agreement in pressor action of the two substances. The amount of the volatile base thus probably identified was, however, insufficient to account for more than a very small part of the pressor action of the extract, which, indeed, retained most of its activity after exhaustive steam distillation. We, therefore, further examined the ergot extract for the presence of p. hydroxyphenylethylamine, the most active of the pressor substances in putrid meat. By extraction from the neutralised extract with amylalcohol, and again from the latter with caustic soda, a solution was obtained containing practically the whole of the pressor substance. 1 Biochemical Journal, n. p. 240. 1907. 2 Barger and Walpole, This Journal, xxxviii. p. 343. 1909.