Cellular growth in organs of dwarf mice during treatment with growth hormone, thyroxine and plasma fractions containing somatomedin activity

Abstract

Abstract. DNA, RNA and protein content of the liver, kidneys and spleen were studied in dwarf mice during treatment with human growth hormone (hGH), thyroxine and plasma fractions containing somatomedin activity (SM-P1 and SM-P4). This investigation has revealed that part of the growth of the liver and all growth of the spleen obtained with the administered preparations, are a consequence of nuclear division. Cell enlargement is not induced in the spleen by either of the preparations used. In the liver a small degree of hypertrophy is obtained with SM-P1. In the kidney both cell number and cell size are stimulated by thyroxine and to a lesser extent by hGH and SM-P1. With regards to the RNA content per cell an increase is obtained with hGH and thyroxine in the liver and in the kidneys also with SM-P1, but not in the spleen. These data demonstrate that semi-purified SM-preparations, like hGH and thyroxine, might be potent stimuli for the restoration of the impaired nucleic acid metabolism in these organs of the Snell dwarf mouse.