Further studies on the effects of pituitary growth hormone (STH) on C3H mice bearing a transplanted mammary adenocarcinoma.

Abstract

Summary The administration of growth hormone to C3H mice bearing a transplantable mammary adenocarcinoma produced a significant increase in body weight, provided the dose of hormone was increased periodically to compensate for a refractoriness developed towards it. In contrast to a previously reported experiment, however, the tumors were significantly smaller than those of the saline-treated controls at the end and during the latter part of the experiment. Repetition of the experiment showed that STH appears to cause an acceleration in the growth rate of the tumor for periods up to 27 days. After this stage the effect seems to be reversed, despite continued increase in somatic growth. Emphasis is placed upon the refractoriness to STH shown in mice by the necessity of increasing its dosage to relatively heroic amounts. The transplanted tumors, especially the more slowly growing ones, proved to be more sensitive in reflecting this refractoriness than the somatic tissues.