HORMONE STUDIES WITH THE ULTRA-CENTRIFUGE II. THE CONCENTRATION OF ANTERIOR LOBE AND PITUITARY-LIKE HORMONES WITH THE ULTRA-CENTRIFUGE1

Abstract

Gonadotropic hormones of pregnant mare serum (Antex), castrate urine and a thyrotropic flavianate extract of beef hypophysis were subjected to 150,000-200,000 g. in an ultra-centrifuge for 4-6 hrs. Marked conc. of mare serum and castrate urine preparations oc-curred; there was little if any conc. of the thyrotropic flavianate extract. In all instances a sludge thrown down in the base of the tubes was without potency. Gonad-stimulating potency of centrifuged extracts was tested by examination of ovary and uterus wt. of injected 21-day-old mice; thyrotropic potency was assayed by wt. response of thyroids of injected day-old chicks.