Societies and Academies

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    LONDON. Royal Society, Jan. 21.—C. Donhoffer and J. J. R. Macleod: Studies in the nervous control of carbohydrate metabolism. When decerebration is performed through the pons in rabbits under amytal anaesthesia, the percentage of blood sugar rises very high after the effects of the anaesthetic have passed off. After pontine decerebration the percentage of lactic acid increases in the blood and the percentage of glycogen decreases in the muscles, but may either increase or decrease in the liver. No relationship exists between the degree of decerebration, hyper-glycaemia, and the percentage of glycogen initially present in liver and muscles, and when previously fasted animals are used it is impossible to account for the hyperglycsemia by the sugar arising from the glycogen which disappears. It is concluded that a process of gluconogenesis is responsible for most of the extra sugar, but it has so far proved impossible to determine the extent to which protein and fat contribute towards its production. In fasted animals, having small percentages of glycogen in the liver and muscles, pontine decerebration fails to induce hyper-glycaemia after double adrenalectomy, or administration of atropine, ergotamine, or amytal. It is concluded that decerebration hyperglycgemia is in large part due to stimulation through the autonomic nerves of some process by which the liver discharges sugar in excess of that available from the glycogen initially present in it. Since amytal paralyses this pathway, it prevents the rise in blood sugar percentage following pontine decerebration, piqure, and asphyxia, but not that due to the injection of large doses of adrenaline.W. T. Astbury, T. C. Marwick, and J. D. Bernal: X-ray analysis of the structure of the wall of Valonia ventricosa.—(1) The cell-wall is built up of two main sets of cellulose chains which form crystallites crossing at an angle maintained remarkably constant through the whole thickness and over considerable areas of the wall. The orientations of the cellulose chains are parallel to the directions of the fine crossed striations which may be detected on the surface of the wall. The extinction directions shown by the wall in polarised light lie between the directions of the cellulose chains and vary in a manner determined by the inter-chain angle and the relative proportions of the chains associated with each orientation.—F. A. Askew, R. B. Bourdillon, H. M. Bruce, R. K. Callow, J. St. L. Philpot, and T. A. Webster: Crystalline vitamin D. Further purification of the antirachitic principle has been achieved by esterification of the crystalline distillation products formerly described as calciferol. The purified calciferol now obtained has an antirachitic activity twice as great as any previously recorded, and appears to be identical with the vitamin D2 of Linsert and Windaus. A simplified process is described for preparing the pure product from the irradiation products of ergosterol without distillation. An account is given of two inactive compounds termed pyro-calciferol and sterol X. Evidence is given of the relations between the crystalline antirachitic products hitherto described, showing that the activity of each of them is due to one common constituent. Thus the vitamin Dj of Windaus is a compound of calciferol (= vitamin D2) and sterol X, and the crystalline distillation products first described contained pyrocalciferol and sterol X, as well as calciferol. (See also NATURE of Oct. 31, 1931, p. 758, and Jan. 9, p. 50.)

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    Societies and Academies. Nature 129, 178–179 (1932) doi:10.1038/129178a0

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