On the physiology of diabetic sugar in the animal economy / by Robert M'Donnell, M.D.

  • Robert McDonnell
Date:
1859
Catalogue details

Licence: Public Domain Mark

Credit: On the physiology of diabetic sugar in the animal economy / by Robert M'Donnell, M.D. 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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    it may become almost painful, if not impossible, to be disunited, are principles often with difficulty carried into practice. I have myself verified most of the conclusions arrived at by Dr. Pavy in his paper On the alleged Sugar-forming Function of theLiver, in Guy's Hospital Reports, 1858, and have repeated his experiments with various modifications. While, therefore, I offer my testimony as corroborative of the results which he has obtained, I feel it right, in giving a resume of his researches, to lay before the reader his own account of the experiments ■which most strongly support the position which he maintains. It had been the conviction of Pavy, as of Bernard, whose pupil he had been, that sugar was being constantly poured into the general circulation from the hepatic veins, and he was en- gaged in prosecuting inquiries into the destruction of the sugar thus formed in the animal economy. This destruction he fancied took place in the lungs, and while engaged in some investigations relative to this subject he found it necessary to abstract blood direct from the right side of the heart of a living animal, by introducing a catheter through the right jugular vein into the ventricle. To his surprise he found the blood thus obtained scarcely at all impregnated with saccharine mat- ter ; so unexpected was this result, and so much at variance with the views wliich he at that time held, that he confesses that he was inclined to the opinion that the blood could not have been fairly drawn from the ventricle, or that perhaps it was accidentally derived from the blood of the descending cava, not yet freely mixed with that coming from the liver. These suppositions he was by degrees obliged to set aside, as he found, from a great number of observations, that blood thus obtained yields the merest trace of sugar under an ordinary and natural condition during life; the reaction of Barreswil's solution with it being so slight as sometimes to be overlooked altogether. In repeating this experiment, I have arrived at results quite in accordance with those of Pavy. If the blood be dexterously withdrawn from the right side of the heart, which is best managed by introducing through the jugu- lar vein a small silver catheter fitted to a pipette, the bulb of which is capable of containing about an ounce, and which has a piece of vulcanized Indian rubber tubing so fixed to it that the blood can be sucked in by the action of the mouth; and if, at the same time, the animal be prevented from making any convulsive movements, scarcely a trace of sugar will be dis- covered in the serum. But if an animal under precisely similar circumstances, so far as regards diet, be killed by pith- ing, and, ten minutes after death, an ounce of blood be collected
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