Chemical and biological characterization of an active substance of the human placenta.

Acetic acid extracts of human term placenta have been fractionated by pH and salt precipitations and by exclusion chromatography on a Sephadex G-75 column. A partially purified fraction (F-II) possessing uterotropic activity in immature and young mice was obtained. This active fraction was submitted to the action of protein denaturating agents (heat, 8 M urea) and of specific proteolytic enzymes (trypsin, alpha-chymotrypsin and pronase). These treatments completely destroy the uterotropic activity showing that the active substance is of protein nature. The administration of F-II to spayed mice did not produce any increase in their uterine weight suggesting that the uterotropic activity would be due to stimulation of the female gonad.

Biological and immunological studies of a placental gonadotropic protein.

Precocious sexual maturity, ovarian weight increase and stimulation of the sex accessory organs in impuber female mice, was induced by a partially purified protein fraction obtained from human placenta. The relationship between this biologically active protein and HCG was studied by a comparative immuno-double diffusion technique (Ouchterlony) and two agglutination inhibition tests. Results showed that this protein with gonadotropic activity is neither immunologically related to HCG nor contaminated with this hormone.