On some physiological actions of ergot / by H.H. Dale.

  • Henry Hallett Dale
Date:
[1906?]
Catalogue details

Licence: Public Domain Mark

Credit: On some physiological actions of ergot / by H.H. Dale. Source: Wellcome Collection.

    4/48 (page 164)
    and I have thought it better to speak of the action as that of “ ergot,” and to mention in the body of the paper the particular preparations used. This seemed the more desirable in view of the possibility that the effects are due, not to one but to two closely associated principles. Dr G. Barger is investigating the matter from the chemical side, and in a later joint paper we hope to deal with the nature of the active substance or substances, their distribution in ergot preparations, and the therapeutic application of our results. This paper is concerned with the action only in so far as it appears to be of general physiological interest. Since the various preparations used in the experiments here described, while free from ergotinic acid, choline and the other depressant impurities of galenical preparations, contain varying proportions of inert matter, it will be understood that indications as to dosage can be no more than rough approximations. Chrvsotoxin, which generally contains about 99°/o of inactive but harmless material, was the form of administration in all the earlier experiments. In many cases the chrysotoxin was dissolved in the smallest possible volume of ethyl alcohol, just enough sodium hydrate added to prevent precipitation on the addition of water, and the solution then diluted with water to a strength of 1 °/o chrysotoxin. In other cases the preformed water- soluble sodium salt was used, prepared by precipitation from a solution in dry ether by means of sodium ethylate. This preparation possesses a good deal of the activity of the original chrysotoxin, but not all, nor even a constant proportion of it. Preparations corresponding to Jacobj’s sphacelotoxin and to Robert’s cornutine were used in many of the later experiments, and were similarly dissolved in dilute sodium hydrate. Their activity varied from 20 up to 100 times that of the average specimen of chrysotoxin. The experiments here discussed are concerned only with such prompt effects of intravenous injection as can be observed directly, or with the aid of mechanical methods of recording, in the anaesthetised or pithed animal. No new observations have been made on the slowly developed effects of administration by the mouth or hypodermically to the intact animal, and these will be dealt with only incidentally. Most of the experiments were made on cats: a few also on rabbits, dogs, monkeys, ferrets, and fowls, the purpose for which each species was used being indicated in dealing with the results of particular experiments. The animals were always anaesthetised with chloroform, ether, or A.C.E. mixture, unless or until the cerebrum was pithed.