THE VITAMIN B e GROUP 663 



doxine-deficient diet containing 0.5 mg per cent of desoxypyridoxine. 73 

 If a change to the deficient diet containing the analogue is made on the 

 day of breeding, the effects noted, such as 10 per cent resorption, are not 

 as drastic as those resulting from placing the animals on the diet prior 

 to breeding. If the animals are placed on the diet 22 days before breed- 

 ing, resorption occurs in all cases and failure of implantation occurred 

 to a significant extent (29 per cent). The percentage of resorptions and 

 number of young born dead increased, whereas the average number of 

 young per litter and average weight of the young decreased with the 

 increase in number of days the animals were maintained on the deficient 

 diet before breeding. Supplementation with pyridoxine on the day of 

 breeding counteracted the adverse effects of the desoxypyridoxine. 73 



Administration of desoxypyridoxine to rats receiving tryptophan 

 causes small increases in the excretion of xanthurenic acid and ky- 

 nurenine, products which are known to be excreted as a result of vitamin 

 B 6 deficiency (p. 428). The increase produced by the analogue in excre- 

 tion of xanthurenic acid and kynurenine was significantly greater in rats 

 partially depleted of vitamin B 6 . Desoxypyridoxine produced this met- 

 abolic dysfunction almost immediately, in contrast with the period of 

 time necessary for occurrence of deficiency symptoms. Supplements of 

 pyridoxine prevented these effects of desoxypyridoxine. 



With mice on a pyridoxine-deficient diet, desoxypyridoxine produces 

 dermatitis, "ring tail" condition, unstable gait and other symptoms com- 

 parable to those produced in the rat. 68 



Desoxypyridoxine fed to an insulin-treated, depancreatized dog on a 

 diet deficient in pyridoxine increased the fasting blood sugar but did not 

 cause glycosuria or affect the hemoglobin, cell volume or serum 

 chlorides. 75 



Administration of desoxypyridoxine to mice and rats causes atrophy 

 of both normal and neoplastic lymphoid tissue. 76 Lymphosarcoma trans- 

 plants showed marked regression following administration of desoxy- 

 pyridoxine. The regression was associated with extensive pyknosis and 

 caryorrhexis of tumor lymphocytes and transformation of tumor cells 

 into apparent multinucleated giant cells. 76 When pyridoxine is given 

 simultaneously with the analogue, the latter has no effect. Similarly, 

 atrophy of the spleen, thymus and lymph nodes has been reported for 

 puppies, chicks and monkeys following the administration of desoxy- 

 pyridoxine. 69 Impairment of the immune response in rats has also been 

 noted, and the anamnestic reaction is abolished in acute pyridoxine 

 deficiency. 76 There is not, however, an increased rate of antibody destruc- 

 tion, as the disappearance of antibodies following passive immunization 

 is not accelerated by a pyridoxine deficiency. 76 A progressive decrease 



