Prostaglandin F2α Receptor in Ovine corpora lutea

Evidence is presented for the existence of a prostaglandin‐F2α receptor in ovine corpora lutea. Prostaglandin F2α was specifically bound to a particulate fraction of this tissue with a dissociation constant of 0.1μM. Prostaglandins F1α, E1 and E2 had considerably less affinity for the receptor whereas prostaglandins A2 and B2 had little or no affinity. From a comparison of the binding constants of various prostaglandins and related compounds it could be concluded that the carboxyl group, the three hydroxyl groups and the 5,6‐cis double bond (but not the 13,14‐transdouble bond) of prostaglandin F2α were all important for binding to the receptor.