A MODIFICATION OF THE PIGEON CROP SAC ASSAY FOR LACTOTROPHIC HORMONE DETERMINATIONS BY MEANS OF THE ADDITION OF PREDNISOLONE

For LTH-determination in biological material without preliminary extraction procedures the pigeon crop sac assay, performed by the micro-method of Grosvenor & Turner(1958), and modified by the addition of prednisolone to the standard or test material was used. Serum samples of lactating women caused no inflammations of the skin of the pigeons, and the crop sacs hardly showed any signs of inflammation. Reaction sites could be measured more easily, and the LTH activities in the plasma were about 3 times higher than in plasma processed by the acetone extraction method of Sulman(1956).