Growth of Hypophysectomized Rats Injected with Growth Hormone and Fed on Different Proteins

Abstract

The growth rates of 23-day-old hypophysectomized rats fed diets containing proteins, lactalbumin, casein and soya proteins of different nutritional qualities were detd. These animals also received a daily injn. of growth hormone. The data demonstrated that soya protein is inferior to either of the 2 milk proteins. However, the superiority of lactalbumin, demonstrable in the growth of unoperated weaning rats, failed to reveal itself in the hypophysectomized animals. The results can be explained on the difference in the protein requirements of the operated animals, although the possibility of special vitamin requirements of such animals was also recognized. In any case, the importance of quality of protein in the diet of rats used for the assay of growth hormone using hypophysectomized rats must be emphasized.