The physiological action of choline and neurine / F.W. Mott.

  • Mott, F. W. (Frederick Walker), 1853-1926.
Date:
1899
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Licence: Public Domain Mark

Credit: The physiological action of choline and neurine / F.W. Mott. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    In carrying this out, we have found that the cerebro-spinal fluid from these cases is much richer in proteid matter than the normal fluid is, and that it contains a basic substance, choline, which is easily accounted for from the decomposition of lecithin, and which is absent in normal cerebro-spinal fluid, or present in such small quantities that it cannot be detected. In our first experiment we took an anaesthetised rabbit, and injected some 30 cub. centims. of the fluid removed, after death, from the cranial cavity of one of these patients. The arterial blood pressure, which was being registered by a mercurial kymograph, fell immediately and continuously, and never rose again. The animal died in the course of a few minutes. This was not due to the nucleo-proteid, which we subsequently found to be present in such fluids, causing intra-vascular coagulation, for the blood was found to be quite fluid ; it was due to the choline which is present. In our subsequent work we used principally dogs and cats, which are hardier animals; hutch rabbits are especially prone to die under circumstances that lead to vascular engorgement of the splanchnic area,* and it is chiefly by dilatation of the vessels in this area that the base choline produces the lowering of arterial blood- pressure, as we shall more fully see in the later sections of this paper. It will be evident from the foregoing introductory remarks, that as the research proceeded it became necessary to make a complete investigation of the action of the alkaloid in question, to which we added a similar investigation of the closely related alkaloid neurine. Our proofs that the toxic substance in the cerebro-spinal fluid is choline, rest partly on physiological and partly on chemical grounds. The physiological proof consists in the identity of the action of the alkaloid with that which is present in abnormal cerebro-spinal fluid ; the chemical proof consists in the application of the recognised tests for the base, and the separation and analysis of some of its compounds. Neurine is a far more powerful poison, and differs considerably from choline both in its chemical and its physiological re-actions. It is not present in the cerebro-spinal fluid of these patients. In order to avoid fallacy from post-mortem changes, or microbic growths, the autopsies were performed as soon as possible after death, in some cases within a few hours. When this was not possible, the bodies were placed in a cold chamber (0° C. or lower) within half an hour after death, until the autopsy was performed. In all cases, too, cultures were made from the cerebro-spinal fluid, and blood of the frontal sinus, and in nearly all instances without result ; this precaution we considered to be necessary, as many of these people die with bladder affection, or ulcerative colitis, and microbic toxins might arise. With a little practice also it soon became perfectly easy to obtain the cerebro-spinal fluid without any admixture with blood. We have never had the opportunity of examining the fluid removed during life ; Leonard Hill, ‘Proc. Physiol. Soc.,’ March 12, 1898. (‘.Journal of Physiol.,’ vol. 22, p. liii.)