THE METABOLISM OF VITAMINS 349 



within a few weeka in man, guinea-pigs, monkeys and dogs. On the other 

 hand, it has been conclusively shown that all of the higher animals need a 

 certain amount of fat-soluble and antineuritic vitamin for proper 

 nutrition, maintenance of normal growth, reproduction and life. It has 

 been suggested by various students of this subject that the antineuritic 

 vitamin is somehow concerned with the maintenance of the proper function 

 of the nervous system, an assumption which is supported by the occurrence 

 of severe paralytic symptoms and degenerative changes in the nervous 

 system of animals fed on a diet deficient in this vitamin. More recently, 

 McGarrison has shown, however, that the nervous system is by no means 

 the only organ affected by this particular vitamin deficiency. 2 A few 

 workers have made the attempt to prove that the antineuritic vitamin 

 has a stimulating action upon various digestive glands, this resulting in 

 an iiicEeased production of secretion. Bickel(e) (1917), for instance, 

 showed that a crude extract of spinach contains a principle with a pharma- 

 cological action similar to that of pilocarpin. Uhlmann(a)(6) (1918) 

 studied the effect of the residue of an alcoholic extract from rice polishings 

 on various digestive glands and the sweat glands. He obtained a marked 

 increase in secretion, following the parenteral injection of the extract. He 

 was furthermore able to show that the same extract caused contraction of 

 intestinal muscle and a fall in blood pressure. The latter effect he attrib- 

 utes to a direct depressing effect on the heart muscle and to vasodilatation. 

 Shortly after this paper had appeared, Voegtlin and Myers(c) (1919) 

 published their findings, which were carried out without a knowledge of 

 Uhlmann's work. They showed that the intravenous injection of a highly 

 purified extract from yeast produced an abundant flow of pancreatic and 

 biliary secretion, resembling in every respect the effect produced by an 

 extract of the duodenal mucosa purified in the same manner as the yeast 

 extract. Alcoholic extracts from liver produced the same effect, and all 

 three extracts were shown to be rich in antineuritic vitamin, when tested 

 as to their therapeutic action on polyneuritic pigeons. As suggestive and 

 interesting as these findings may be, it should be emphasized that the 

 physiological effect noted by all these observers may have been due to some 

 highly active impurity and not the vitamin per se. 



Dutcher (1918) has recently suggested some relation between the 

 antineuritic vitamin and oxidative processes, as he observed that the tissues 

 of polyneuritic birds showed a marked reduction in catalase and that the 

 catalase activity was again restored to normal after the administration of 

 this vitamin. He believes that this substance increases the production 



of catalase. . . 



Funk (1919), Braddon and Cooper (1914) claim that the antmeunt 

 vitamin is essential for the metabolism of carbohydrates, a view which i, 

 not shared by Vedder (1918). 



'For further details see chapter on beriberi. 



