Inhibitory Effect of Pyridoxine Deficiency on Growth of a Transplanted Tumor in Rats. ∗

Summary

Two experiments were conducted using rats of the Marshall 520 strain depleted in vit. B₆ by the use of a deficient diet and 4-desoxypyridoxine. Osteogenic Sarcoma 344 was transplanted into the deficient animals, a pair-fed group and an ad libitum group. Desoxypyridoxine was removed from the diet of the deficient animals on the day of tumor transplant. In Exp. 1 daily measurements of the tumor showed a marked inhibition of the growth of the tumor in the deficient animals as compared to the control groups. The mean weight of the tumor and also the mean weight as a percentage of final mean total body weight were also decreased. In a second experiment larger, more mature animals were used. Tumor inhibition in the deficient animals was again observed, although it was not so striking as in the first experiment. No histological differences in the tumor were noted in either experiment with the exception of increased hemorrhage and necrosis in the neoplasms of the ad libitum animals.