PURIFICATION AND PROPERTIES OF A COMPONENT OF THE PITUITARY GLAND WHICH PRODUCES LIPEMIA IN THE RABBIT1

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Abstract
A modification of the previously described method for the preparation of Fraction H from hog pituitary glands by alkaline extraction, fractional precipitation with acetone, and chromatography on IRC-50 resin is presented. The yield is 8 mg. per gram of lyophilized hog pituitary glands. As little as 0.125 mg. of Fraction H causes a 6 fold rise in the serum free fatty acid level, and as little as 3 mg. causes a 4 fold increase in the serum total lipid level of the rabbit. Fraction H prepared b}r this method contains 0.8% growth hormone, 0.007%, oxytocin, 0.00005% melanocyte-stimulating hormone, and no detectable amount of the other 6 recognized pituitary hormones. The active substance in Fraction H is inactivated by trypsin or by exposure to 0.1N NaOH at 100° C, is non-dialyzable, and is insoluble in 5% trichloracetic acid. The biologic activity of Fraction H is not diminished by digestion with pepsin or by exposure to 0.1N HC1 at 100° C. The active substance or substances in the peptic digest of Fraction H are dialyzable and are soluble in 5% trichloracetic acid. Chromatography of Fraction H on DEAE-cellulose gives a further 5-fold purification of the active component. The resulting preparation (labeled Fraction L) moves as a single substance in paper electrophoresis.