Prostaglandin F2α Receptors in Bovine Corpora Lutea Throughout Pregnancy1

Abstract

These studies were undertaken to examine whether or not receptors for prostaglandin PGF₂α were present in bovine corpora lutea throughout pregnancy. The results show that cell membranes prepared from corpora lutea throughout pregnancy bind ³H-PGF₂α reflecting the availability of its receptors. Variations in the receptor numbers rather than in the receptor affinities appear to account for the variations in ³H-PGF₂α binding throughout pregnancy. The fact that PGF₂α receptors are present in corpora lutea throughout pregnancy and yet luteolysis occurs only at the end of pregnancy suggests that PGF₂α receptor availability is not a limiting factor in the onset of luteolysis.