Further studies on gonadotropin-inhibiting substances excreted in human urine.

Abstract
Partial separation of human urinary substances which have properties to suppress ovulation induced by PMS [pregnant mare serum gonadotropin] and HCG [human chorionic gonadotropin] in mice was attempted by gel filtration on Sephadex G-100 and ultrafiltration using the Amicon Diaflo membranes UM-2 and UM-10. In addition to a thermostable inhibitor which has a MW more than 10,000, the presence of a heat-labile inhibitor with a MW less than 1000 was demonstrated.