Immunohistochemical Demonstration of Prostaglandin E2 in Cultured Bovine Embryos

Antiserum to prostaglandin (PG) E2 and indirect immunofluorescence were used immuno-histochemically to demonstrate the presence of PGE2 in unfertilized and fertilized bovine eggs matured in vitro, and embryos from the 2-cell to hatched blastocyst stage developed in vitro. Fluorescence showing the presence of PGE2 was found in the cytoplasm of all the eggs and embryos, though its intensity was weak in unfertilized eggs to morulae, and was strong in blastocysts. No difference in the intensity was observed between unfertilized and fertilized eggs, among embryos at the cleaving stages, and among those at the early, expanded and hatched blastocyst stages.