Further Studies on the Purification of Human Thyrotropin

Thyrotropin activity was concentrated 1400-fold from acetone dried human pituitary glands. The final product had a TSH potency of 10.4 Human International Units/mg. The yield of activity was 34%. The glands were extracted by percolation in stepwise sequence with 76% ethanol-2% NaCl, 50% ethanol-5% NaCl and water. The 50% ethanol-5% NaCl solvent front contained most of the TSH, LH and FSH. TSH and LH were separated from FSH and most of the contaminating GH by adsorption of the TSH and LH at pH 6 on carboxymethyl cellulose. The TSH was then separated from the LH by adsorbing the TSH on diethylaminoethyl cellulose at pH 9.5. An LH fraction with a potency of 5.5 mg equivalents of NIH-LH-S-1/mg was obtained that had a TSH activity of only 0.01 Human IU/mg. This LH fraction was 920 times more potent than the acetone dried glands. By the above procedure the yields of TSH were superior, of FSH and LH were the same, and of GH and prolactin were inferior to those of other laboratories that used more aqueous methods of extraction. (Endocrinology83: 721, 1968)