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

  • Dale, Henry H. (Henry Hallett), 1875-1968.
Date:
[1906?]
Catalogue details

Licence: Public Domain Mark

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

    5/48 (page 165)
    The effects of intravenous injection, the mode of administration used throughout these experiments, are divisible into two classes, corresponding to a primary or stimulant, and a secondary or paralytic stage of the drug’s action. It will be convenient, however, as giving a more connected picture of the sequence of events, to deal, in the first place, separately with each organ or system on which observations have been made. 1. The Circulatory System. Primary or stimulant action. The first definite laboratory demon¬ stration of the stimulant effect of ergot on the peripheral arteries was given by Robert1. The gangrenous phenomena which he observed in the comb and other peripheral structures of the fowl and the pig, as the result of administering sphacelinic acid, were attributed by v. Reck¬ linghausen, who investigated the phenomena histologically,to “powerful and persistent constriction of the arterioles.” In contrast to this repeatedly confirmed and now familiar action on the cock’s comb, the results of observing the effect on blood-pressure have been very- variable and unsatisfactory. Setting aside, as merely misleading, the numerous observations on the depressant effect of crude extracts given intraven¬ ously^, the recorded results with such comparatively pure preparations as sphacelotoxin and cornutine are surprisingly inconclusive. Robert gave an intravenous injection of the sodium salt of sphacelinic acid to a rabbit and observed a rise of blood-pressure, beginning 8—10 minutes after the injection, followed by strychnine-like spasms of the whole animal and cessation of respiration, with which the blood-pressure fell rapidly. In a rabbit deeply chloralised, or with the cord cut in the neck, he observed no trace of these phenomena. This description may well raise a doubt as to whether the whole phenomenon be not asphyxial in origin: but that supposition seems to be excluded by the fact that Robert observed a larger rise of pressure in a curarised rabbit with artificial respiration. Under the same conditions he observed a rise of pressure with cornutine. Jacobj3, wrho obtained with his preparations similar effects on the cock’s comb to those observed by Robert, found but slight effects on 1 loc. cit. 2 Cf. a recent paper by Sollmann and Brown (Journal American Med. Assoc. July 22, 1905), who give references to moat of the papers dealing with similar ex¬ periments. 3 loc. cit. 11—2