Effect of Synthetic Steroid or Phenanthrene Compounds upon Weight Gain and Feed Efficiency of Rats.

Summary Studies have been made of the effects of feeding 2 compounds, Ro-2-7239 (2-acetyl −7 - oxo −1,2,4,4a,4b,5,6,7,9,10,10a -dodecahydrophenanthrene) or SC −6582 (17α - methyl −17 - hydroxy −5(10) - es-tren-3-one), to rats at levels of .75, 1.0, 1.5, or 3.0 μg/g of diet. Equalized or ad libitum feeding was employed with weanling or young adult normal or castrate males or normal females. Compound Ro-2-7239, but not compound SC-6582, significantly inhibited both weight gain and feed efficiency in normal male rats. No significant changes in response to either compound were noted in castrate males or normal females. Compound SC-6582 at the 3 μg/g level, but not compound Ro-2-7239, produced significant increases in size of adrenals in normal male rats. Neither compound at the 3 μg/g level produced significant alteration in size of pituitary, thyroid, testes, or of uterus.