The action of certain esters and ethers of choline and their relation to muscarine / by H.H. Dale.

  • Henry Hallett Dale
Date:
[1914?]
Catalogue details

Licence: In copyright

Credit: The action of certain esters and ethers of choline and their relation to muscarine / by H.H. Dale. Source: Wellcome Collection.

    43/48 (page 187)
    well be interpreted as a “nicotine” action, and it is in accord with this view that it is unmodified by atropine. In that case one would expect that the nitric ester and ethyl ether, with their intense muscarine-like action on the mammalian pupil, and, in the case of the ethyl ether, comparatively weak nicotine-like action, would be less efficient constrictors of the bird’s pupil. The experimental comparison shows that they are both, in fact, more potent myotics, in this case also, than the nitrous ester. It is clear, then, that the distinction between “muscarine” and “nicotine” activity cannot be made with absolute sharpness, when effects on different species are included in the comparison. Nor is there any evidence enabling us to regard one group of the molecule as responsible for the one type of action, and another for the other. One can merely conclude that there is some de¬ gree of biochemical similarity between the ganglion cells of the whole involuntary system, and the terminations of voluntary nerve-fibers in striated muscle, on the one hand, and the mechan¬ ism connected with the peripheral termination of cranio-sacral involuntary nerves on the other. We have a whole group of substances which affect both, and, in the case of the bird’s sphincter iridis, a structure which in some respects forms a con¬ necting link between the two types of biochemical affinity. There does not seem to be the same relation between the affinities of ganglion cells and of the terminal mechanism con¬ nected with the true sympathetic system. By methylating com¬ pletely the animo-group of a sympathomimetic amine one might expect that a base would be produced which would have a nico¬ tine action and a sympathomimetic action. In no case has this been observed. In some cases, as shown by Barger and myself, a substance of purely nicotine-like action results (e.g. hordenine methiodide). On the other hand from sympathomimetic bases of the simple aliphatic series, such as isoamylamine and hexylamine, quarternary ammonium bases are produced which, as was shown long ago by Schmiedeberg and Harnack,26 and by Jordan,27 combine a muscarine and nicotine action, like the choline 26 Schmiedeberg and Harnack: Arch. f. exp. Path. u. Pharm., vi, 101, 1877. 27 Jordan: Arch. f. exp. Path. u. Pharm., viii, 15, 1878.