Abstract
Purified preparations of luteinizing hormone isolated from human, bovine, porcine and equine pituitary glands, and from human urine, have been compared to ovine LH with respect to their chromatographic behavior on columns of Sephadex G-100, and in a sucrose density gradient system. The studies indicate a close similarity in the molecular weight of all the LH''s studied, with the exception of the equine LH. Estimates by the gel filtration method of Whitaker indicate that the heterologous LH''s behave as though they had a molecular weight of 45,000, while sucrose density gradient studies suggest a molecular weight in the range of 25,000-33,000.