Ability of an Extract of Pig Corpus Luteum to Inhibit Binding of 125l-Labeled Human Chorionic Gonadotropin to Porcine Granulosa Cells

Abstract

Porcine corpus luteum tissue contains an inhibitor of binding of iodinated human chorionic gonadotropin to porcine granulosa cells. The inhibitor was present in the 1000, 30,000 and 105,000g supernatants of the corpus luteum but not in those of nonluteal ovarian tissue, granulosa cells, lung, or heart tissue. The inhibitor appeared only after storage in the freezer for from 1.5 to 11 wk. Freezing heart, lung, or nonluteal tissue for a comparable time period did not lead to an increase in inhibitory activity.