Immunohistochemical detection of prostaglandins in preimplantation embryos of hamsters, rats and rabbits.
Antisera to prostaglandins (PGs) E2 and F2α and indirect immunofluo-rescence were used to immunohistochemically demonstrate the presence of PGE2 and PGF2α in preimplantation embryos of hamsters, rats and rabbits. Fluorescence showing the presence of both PGF2 and PGF2α was observed in the cytoplasm of the eggs and embryos of all those species at the stages of unfertilized 1-cell to blastocyst. The intensity of the fluorescence was always weak in the eggs and embryos of hamsters, while strong at the 1-cell stage of rabbit eggs and 1-cell through 8-cell stages of rat eggs and embryos, but was weakened at the rest of the stages. In the 1-cell eggs of such species, no difference was observed in the in tensity of the fluorescence between the unfertilized and fertilized. These results, then, have clarified that the preimplantation embryos of hamsters, rats and rabbits constantly contain PGE2 and PGF2α in their early develop-mental stages.