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.

    5/48 page 149
    investigation. These were three esters, those of acetic, nitrous, and nitric acids, and one ether, the ethyl-ether. This paper is mainly concerned with the details of the action of these four substances. Concerning numerous less active substances, all bearing some chemical relation to choline, which were tested in the course of the investigation, I can in most cases record only a rough estimate of relative activity, usually based on their effect of the cat’s blood pressure. A few of the experiments have been made on intact animals, with hypodermic injections of the drug. In all other experiments, in which a living animal has been used, it has been fully anaes¬ thetised throughout the experiment, usually with chloroform followed by ether, except in cases where the anaesthetic was stopped after the brain had been completely destroyed. All the substances tested, except for a few which could be obtained pure commercially, have been prepared synthetically for me by Mr. A. J. Ewins who will elsewhere describe the prep¬ aration of such as are new. THE ACTION OF THE CHOLINE ESTERS OF ACETIC, NITROUS AND NITRIC ACIDS, AND OF CHOLINE ETHYL-ETHER As stated above all these substances have an action conforming to the general muscarine type, one of them, the nitrous acid ester, having been hitherto commonly known as “synthetic muscarine,” though its difference in some features of its action from the nat¬ ural muscarine has been recognized since Bohm’s5 paper in 1885. It will be convenient to take the different organs and systems separately and compare the actions of the four substances on each in turn. It will be clear that three of the group—the nitrous and nitric acid esters and the ethyl-ether—have an action in most respects closely similar, while acetyl-choline occupies a some¬ what unique position, due, as will be suggested, to the facts that it is an extraordinarily active but extremely unstable substance. 5 Bohm: Arch. f. exp. Path. u. Pharm., xix, 187, 1885.
    digitised image 1
    digitised image 2
    digitised image 3