Experimental rickets : the effect of cereals and their interaction with other factors of diet and environment in producing rickets / by Edward Mellanby.

Edward Mellanby

Date:: 1925

Credit: Experimental rickets : the effect of cereals and their interaction with other factors of diet and environment in producing rickets / by Edward Mellanby. Source: Wellcome Collection.

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$fa-tty substance or was only associated with the fatty substance. An extension of this work is to be seen in the observations of Hart. Miller, and McCollum [41] on the effect of rations containing a large amount of wheat on pigs. They produced malnutrition and degenerative changes in the nerves similar to those found in beri¬ beri by diets containing excessive cereals, but these authors point out that the pathological changes in the spinal cord were due to the inherent toxicity of the grain and not, as in beri-beri, to a deficiency of vitamin B. In these feeding experiments on swine the toxic effect of the wheat could be greatly mitigated by additions to the diet of alfalfa and commercial meat scraps. It was suggested that the beneficial effects of these additions were due to their vitamin A content, the salt mixture, better proteins, and a liberal supply of calcium phosphate. Osborne and Mendel [3] were unable to confirm the results of McCollum, Simmonds, and Pitz [40] as to the toxic action of wheat germ on growing rats, but the diets used by Osborne and Mendel were different from those used by McCollum, Simmonds, and Pitz. They contained, for instance, 9 per cent, butter fat, as against 2 to 5 per cent, present in McCollum’s diets. This is an important point, because, both according to the results of McCollum and his colleagues and the experiments described in the present publication, the detrimental effects of wheat germ can be easily antagonized by other constituents of a normal diet. There was no reason, however, to believe that the substance in wheat germ which interfered with the growth of rats in the experiments of McCollum, Simmonds, and Pitz had anything to do with the rickets-producing effect of cereals mentioned above. Before describing some of the experiments made to test the question as to the influence of the fat content of oatmeal and wheat germ on bone-calcification, some points, including the mode of preparation of these fatty substances, will be mentioned. Two methods of preparation have been used. (1) The extraction of oatmeal and wheat germ with fat-solvents such as acetone and ether. In the case of oatmeal it is necessary to dry it before extraction with ether. (2) Saponification by heating with alcoholic caustic soda and solution of the fatty acids into petrol ether. 200 gms. of cereal, 44 gms. of caustic soda in 40 c.cms. of water and 500 c.cms. methylated spirit were heated in a flask with reflux condenser for \ to 1 hour. When the unsaponifiable substances were required, the mixture was twice extracted with petrol ether while alkaline. After this it was acidified and the saponifiable sub¬ stances extracted twice with fresh petrol ether. Sometimes the saponifiable and unsaponifiable substances were obtained together by acidifying directly after heating with soda and then extracting with petrol ether. The following figures show the amount of the different products obtained by the above-described methods. Oatmeal. On drying loses 9 per cent, of its weight. Dried oatmeal, on saponification with soda, gives 0-15 per cent-$