Vitamin F in Relation to the Development of the Thyroid and Thymus of Suckling Young.

Abstract

When high protein diets, adequate in all the known dietary constituents excepting Vitamin F, are fed to lactating rats, the young, besides manifesting the untoward symptoms previously described, 1 give evidence of abnormal glandular development. The thymus gland is much smaller than that of normal animals of the same age or weight, while the thyroid is much larger. Among our stock fed animals the thyroid was found to average 0.23% of the body weight, whereas the thyroid of the young of the animals receiving high protein diets averages 0.40% of the body weight. When starch free yeast was added to the high protein diet, the thyroid averaged 0.22% of the body weight. When low protein was substituted for high protein in the basal diet, the thyroid averaged 0.28% of the body weight.

The young of animals receiving low protein diets to which was added respectively glycin and alanine, amino acids known to stimulate metabolism, developed symptoms comparable to those of the young of rats receiving high protein diets. The influence of these additions on the thymus and thyroid also was similar. The thyroids of the young of the animals receiving glycin averaged 0.40% of the body weight whereas those of the young of the animals receiving alanine averaged 0.30% of the body weight. Glutamic acid, known to be low in its stimulating effect, caused no hypertrophy; the weight of the glands of the young receiving this averaged 0.23% of the body weight.

The average weight of the thymus gland of the young of rats receiving the high protein diet without added antineuritic vitamin was 0.11% of the body weight. When Vitamin F was added the thymus averaged 0.43% of the body weight.