Are glucocorticoids auto- and/or paracrine factors in early bovine embryo development and implantation?

We determined the transcript content of three genes involved in the metabolism of glucocorticoids (GC) in bovine in vitro fertilized embryos (2-blastomere stage until hatched blastocyst), trophoblast as well as the oviduct (Day 2-4 of the estrous cycle) and endometrium (Day 16 of the cycle and pregnancy). Since mRNA expression of the glucocorticoid receptor and two enzymes responsible for GC production (11β-HSD1 and 2) was demonstrated in the embryos in all pre-implantation stages as well as in the endometrium and oviduct, it is suggested that GC may serve as auto-/paracrine factors in the development of bovine pre-implantation embryos.