VII. GUINEA PIG ANTISTIFFNESS FACTOR 591 



LM (lid not lespoiul at all to glucosylglyciiie under these conditions, al- 

 though thoy were stimulated bj' yeast extract. *^^ 



The relative ^superiority of glycine o\-er other amino acids in producing a 

 biologically active material with glucose, and the strong inhibition produced 

 with alanine, appear to confer a measure of specificity upon the heat activa- 

 tion reaction and to raise the possibility that one or at most a few factors 

 may be in\'olved. Presumably these represent conversion products from 

 glucosylglycine, since the latter compound possesses relatively low activity. 

 The role of phosphate is not yet clear. Further research should disclose the 

 nature of these factors, as well as their relation to the products of the Mail- 

 lard "browning reaction."'-® The latter appears to be a more general reac- 

 tion between carbohydrates and amino acids, resulting in a net loss of 

 nutritional value of the amino acids toward higher animals.*^ 



VII. Guinea Pig Antistiffness Factor 



A syndrome in guinea pigs was described several years ago, whereby these 

 animals developed characteristic joint stiffness on diets high in milk 

 (Wulzen and Bahrs'-*' '-^). When adequate greens were given, the animals 

 maintained normal health. Intermediate degrees of stiffness at the wrist 

 joints were detected in the animals on the milk diets, and an assay method 

 was developed which attempted to place the stiffening (produced at least 

 in part by the deposition of calcium phosphate in the joints) on a quantita- 

 tive basis. Constituents of the diet were sought which might protect the 

 animals against the onset of stiffness, and it was believed (van Wagtendonk 

 and Wulzen'^") that such a protective factor could be obtained in pure form, 

 either from raw cream or from sugar cane juice. On the basis of this ap- 

 proach, the existence of a nutritional principle, the "antistiffness factor," 

 was claimed, and methods were given for its isolation from cream'^" and 

 from cane juice. '^' 



The existence of the syndrome has been confirmed by other experi- 

 menters'-^^' '^^ and has been described in detail in a review of the subject by 



'" D. Rogers, T. E. King, and V. H. Cheldelin, uiipuljlished. 



»26 L. C. Maillard, Co7npt. rend. 154, 66 (1912). 



»" A. R. Patton, Xutiition Revs. 8, 193 (1950). 



128 A. M. Bahrs and R. Wulzen, Proc. Soc. Exptl. Biol. .Med. 33, 528 (1936). 



>" R. Wulzen and A. M. Bahrs, Am. J. Physiol. 133, 500P (1941). 



'3« W. J. Van Wagtendonk and R. Wulzen, Arch. Biochem. 1, 373 (1943). 



"1 W. J. van Wagtendonk and R. Wulzen, /. Biol. Chem. 164, 597 (1946). 



''- J. J. Olesoii, !•]. C. \iu\ Donk, S. Bernstein, L. Dorfman, and Y. Sul)l>aRo\v, ./. 



Biol. Chem. 171, 1 (1947). 

 "3 H. G. Petering, L. Stubberfield, and R. A. Delor, Arch. Biochem. 18, 487 (1948). 



