The simultaneous isolation of the human pituitary hormones. II. The luteinizing hormone

The main purpose of the work is the isolation of luteinizing hormone (LH) from frozen human pituitaries. The procedure for the processing of the glands included the steps described by P. Roos [22] for the preparation of the follicle stimulating hormone (FSH) slightly modified and adapted to our conditions. After thawing, the pituitaries were homogenized in 0.03 N Naphosphate buffer, pH 5.7. The protein bulk containing growth hormone (GH) was separated by precipitation with saturated ammonium sulfate (v/v). The supernatant containing gonadotrophins, obtained by centrifugation, was fractionated by chromatography on DEAE cellulose, the first peak being further fractionated by column gel-filtration on Sephadex G-100 after a previous concentration by dialysis against polyvinylpyrolidone 10%. The first peak obtained by this last fractionation was considered for the time being, as pure LH. The extraction and fractionation steps were followed by disc polyacrylamide gel electrophoresis and by radioimmunoassay measurement of the LH concentration. Studies concerning the homogeneity and the biological activity of our LH preparation by comparison to the LH preparations recommended by WHO, are in progress in our laboratory.