Lesions of the central and peripheral nervous systems produced in young rabbits by vitamin A deficiency and a high cereal intake / by Edward Mellanby.

  • Edward Mellanby
Date:
[1935?]
Catalogue details

Licence: In copyright

Credit: Lesions of the central and peripheral nervous systems produced in young rabbits by vitamin A deficiency and a high cereal intake / by Edward Mellanby. Source: Wellcome Collection.

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    the absence of vitamin A and carotene. It was hoped that it would be easier to continue this part of the work on smaller and cheaper animals. Thus, it happened that the diet of many experimental rabbits in this series contained either ergot, or some extract or residue of this substance. As the work progressed, however, it became more and more questionable whether ergot affected the nervous system of rabbits even in the absence of the protective substances. In any case its neurotoxic action did not seem as potent in the rabbit as in the dog under the experimental conditions so far tested. It is certain that most, if not all, of the specific nervous lesions to be described can be readily produced in rabbits by withholding carotene and vitamin A and without giving ergot or ergot derivatives. Although the present investigation has been fairly extensive and includes the examination of central and peripheral nerves as well as many groups of cells and ganglia in a large number of rabbits it is by no means complete. A neurological expert would undoubtedly find many other points of interest both in the behaviour of the animals and in the lesions of the nervous system produced by these specific nutritional conditions. This work, however, may lead others to extend the inquiry. Experimental Conditions. Litters of rabbits of eight to ten weeks old were used. The basal diets had to be such that they were compatible with good health and growth during the period in which the specific lesions developed. The following diet deficient in carotene and vitamin A was found to fulfil this object. The main ingredients were 4 parts of oats and 1 part of bran to which calcium carbonate was added to form 1*5 per cent, of the mixture; lemon-juice was given in some of the experiments as a source of vitamin C. According to the age of the rabbit, 40 up to 70 grm. of the oats-bran mixture, together with a constant amount of 10 grm. of dried alfalfa which had been heated at 120° C. for thirty-six hours, were given daily. The alfalfa was ground to a fine powder and then heated in thin layers on trays in an electric oven and stirred frequently during the heating process in order to allow full exposure to the air. By this means its carotene content could be entirely destroyed. A point of importance for the production of severe lesions is the degree of destruction of the carotene in the alfalfa. If it be only partially destroyed, there may be little or no degeneration, or it may develop slowly and not be severe. For intense lesions to develop rapidly the heating and
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