Effects of Vitamin B 12 on Diethylstilbestrol and Thyroprotein Action in Male Rats. ∗ †

Summary

The effects of crystalline vit. B₁₂ on several actions of diethylstilbestrol and thyroprotein were determined in 100 young male albino rats. Diethylstilbestrol and thyroprotein were incorporated into the ration in amounts of 0.10 and 0.16% respectively, and vit. B₁₂ was injected subcutaneously in doses of 0.2 or 0.4 fig daily. Vit. B₁₂ partially counteracted the growth-retarding action of these two hormones when given individually or together, and also increased food consumption. The vitamins did not alter the ability of diethylstilbestrol or thyroprotein to depress testes weight or the ability of the former to increase the weight of the seminal vesicles.

Addendum. Further data obtained since this manuscript was submitted indicate that vit. B₁₂ probably does not alter the turnover of thyroprotein in the rat. The increase in the basal metabolism of rats given thyroprotein was found to be unaffected by vit. B₁₂ administration.