EN
This study was performed on the European bison and aimed at determining the existence of a placental dopamine ß-hydroxylase (DßH; EC 1.14.17.1) protein expression localised by fluorescent immunohistochemistry (F-IHC); and at identifying a profile of the DßH expression throughout the placenta development. Placentomal sections were prepared from the placentas collected from females during two pregnancy stages (60 and 120 d post coitum). F-IHC was performed with the use of primary rabbit serum against DßH that was visualised by a secondary donkey F(ab)₂ IγG fragment against the rabbit IγG-conjugated with CY₃. The DßH expression was demonstrated within the maternal parts (caruncles) of the placentome structures developed within the synepitheliochorial placenta in the first half of pregnancy. The DßH expression profile is associated with the maternal blood vessel development as the pregnancy advances. It seems that the DßH expression is involved in the regulation of the endometrial angiogenesis, and may play an important role as a neurotransmitter existing in the European bison placenta. This is the first paper describing the expression of DßH in the European bison.