Gonadotrophic activity of the guinea-pig placenta during pregnancy

Publisher Website
Google Scholar
Abstract
A gonadotropic substance was extracted from placentae and subplacentae of guinea-pigs. Biological and immunological assays of these tissues obtained on days 10-63 of pregnancy showed the highest mean concentration of the gonadotropin on day 18. Extracts chromatographed on Sephadex G200 had components active in the radioimmunoassay system for hCG [human chorionic gonadotropin], hCG-.alpha. and hCG-.beta. subunits. The elution profiles of these extracts were similar to those obtained with human term placentae and purified hCG and its subunits. The guinea-pig placental extracts also cross-reacted with an antiserum to the .beta. subunit of ovine lutropin, as did hCG. The biological activity of placental and subplacental extacts and of the hCG standard was neutralized by anti-hCG serum. There is a strong similarity between hCG and the substance extracted from guinea-pig placentae which may therefore have a luteotropic function similar to that of hCG.