Xerophthalmia, trigeminal degeneration and vitamin A deficiency / E. Mellanby.

  • Mellanby, Edward, Sir, 1884-1955.
Date:
[1934?]
Catalogue details

Licence: In copyright

Credit: Xerophthalmia, trigeminal degeneration and vitamin A deficiency / E. Mellanby. Source: Wellcome Collection.

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    612.392.013A [617.713—005.8 + 616.833. 15-—003.8 XEROPHTHALMIA, TRIGEMINAL DEGENERA¬ TION AND VITAMIN A DEFICIENCY. E. Mellanby. Pharmacology Department, Sheffield University. (Plates LX.-LYL) It is disconcerting at first sight to be faced with the fact that two of the main lesions produced in young animals by diets deficient in vitamin A and carotene are so dissimilar, namely (1) hyperplasia and metaplasia of epithelium and mucous membranes, often accompanied by the invasion of these areas by micro-organisms and the production of local infective foci (Mori 1922, Wolbach and Howe 1925, Goldblatt and Benischek 1927, Green and Mellanby 1928,1930), and (2) degenera- ; tive changes of medullated nerves both in the central and peripheral nervous systems (Mellanby 1926, 1930, 1931, 1933). Two such different morbid changes do not appear to have any relation to one another. On the other hand, since the chief causative agent or agents in both cases is the same, it is clearly necessary to make the attempt to correlate these phenomena. The present publication, therefore, deals with an investigation whose object was to see whether there was a possible connecting link which could bring them into close association. It is true that the investigation deals with lesions of only one organ, the eye, but if evidence of a relationship can be produced in this case, it is probable that a similar mechanism holds in other organs where epithelial changes and infective foci are commonly produced by ,a deficiency of vitamin A in the diet. In previously published accounts describing the effect of vitamin A deficiency on the nervous system of experimental animals, I have shown that the resulting nerve degeneration affected both the central and ! peripheral systems (Mellanby, op. cit.). In the former, ascending fibres, both exogenous and endogenous, seem to be principally affected; in the latter, the afferent rather than the efferent nerves. It was the idemyelination seen in the medullated afferent nerves which suggested The clue for the association of nerve degeneration and peripheral infective lesions, for it seemed possible that xerophthalmia and the subsequent Invasion of the cornea and eye generally by micro-organisms might be (secondary to a loss of the trophic control normally exerted by the