X. EFFECTS OF DEFICIENCY 267 



diet toward (ho cud of the hictalioii period. These .symptoms could he 

 alleviated by (he administration of 10 7 of pyridoxine per day, but even 

 50 7 of pyridoxine per day could not protect healthy rats against similar 

 convulsive seizures induced by sound. The inclusion of 25 to 150 7 of 

 pyridoxiiu^ per day in (he diets of rats proteeted them against spontaneous 

 seizures but not against sound-induced seizures; with higher levels of 

 pyridoxine the seizures were both delayed and less severe. Davenport and 

 Davenport" demonstrated that the pyridoxine-deficient rat showed in- 

 creased l)rain excitability measured l\v the decrease in electroshock thresh- 

 old. Administration of pyridoxine and/or glutamic acid increased the 

 threshold, whereas, tryptophan, which intensifies the Be deficiency, reduced 

 it. These observations suggest that maintenance of the transaminase sys- 

 tem is essential for normal brain function. 



Vitamin Be-deficient rats often exhibit muscular dystrophy, especially 

 in the cardiac region.^^' ^^ 



Since vitamin Be is intimately involved in the decarboxylase'*" and trans- 

 aminase^^ enzyme systems, it is not uncommon to observe disturbances in 

 protein metabolism in \dtamin Be deficiency. Acrodynia is more severe in 

 pyridoxine-deficient rats fed a high protein diet than in rats fed a low 

 protein diet.^- Peretti^^ ■ ^"^ observed that Be deficiency had no effect on 

 nitrogen balance or nitrogen metabolism, but Haw^kins et al.^'^ could in- 

 crease the fasting blood levels of urea and non-protein nitrogen l)y feeding 

 pyridoxine-deficient rats on a high protein diet. Beaton ct al}^'^ also demon- 

 strated a significant increase in the fasting level of blood urea, which, 

 they claimed, was the result of a true metabolic disturbance and not renal 

 failure. The avitaminotic rats also exhibited an increased urinary nitrogen 

 excretion, suggesting an impairment in ability to utilize dietary nitrogen. 

 Terroine^^ depleted young male rats of vitamin Be on a high protein diet; 

 when they were then placed on a protein-free diet, the normal rats lost 

 weight more rapidly than did the deficient animals. Total urinary urea, 

 ammonia, and amino nitrogen were higher in deficient than in normal rats. 



=■ V. D. Davenport and H. W. Davenport, J. Nutrition 36, 263 (194S). 



28 W. Antopol and C. E. Schotland, ./. Am. Med. Assoc. 114, 1058 (1940). 



2^ R. M. Thomas, E. Mylon, and M. C. Winternitz, Yale J. Biol. Med. 12, 345 U'-'IO). 



3« E. F. Gale, Advances in Enzymol. 6, 1 (1946). 



" V. Schlenk and E. E. Snell, /. Biol. Chem. 157, 425 (1945). 



32 L. R. Ceiocedo and J. R. Foy, Arch. Biochem. 5, 207 (1944). 



" G. Peretti, Boll. soc. ital. biol. spcr. 16, 396 (1941). 



" G. Peretti, Boll. soc. ital. biol. spcr. 17, 324 (1942). 



35 W. VV. Hawkins, M. L. MacFarland, and E. W. McIIcnn. ./. Biol. Chem. 166. 223 



(1946). 

 35" J. R. Beaton, J. L. Bearo, J. M. White, and E. W. Mi-nenr\ , ./. Biol. Chem. 200, 



715 (1953). 

 3^ T. Terroine, Arch. sci. phijsiol. 4, 91 (1950). 



