The mammalian oviduct: Aspects on auto-and paracrine mechanisms

This review will present a characterization of basic molecular processes in the mammalian oviduct. Oviducts of the cow (Bostaurus) were examined during the various cycle stages using a combination of cell biology- and molecular-biology techniques [reverse transcriptase polymerase chain reaction (RT-PCR), RNase protection assay (RPA), immunohistology, radio-immunoassay (RIA), receptor-assay, cell culture]. In detail the oviductal expression of the following components was analysed: fibroblast (FGF) and vascular-endothelial (VEGF) growth factor systems; extracellular matrix (ECM) enzymes such as plasminogenactivator (PA) and matrixmetalloproteases (MMP), adrenergic receptors (α2 and β2 AdR) and an anti-oxidative protein (glutathionperoxidase = GPx). A specific cycle-dependant and local regulation of the expression could be demonstrated, not only for growth factors such as FGFI and VEGF but also for ECM components. Remarkable progesterone-dependent increases of the β2 adrenoceptor concentrations were found in the oviductal epithelium. New observations showed the presence of antioxidative enzymes (GPx) in the bovine oviduct possibly interacting with the gametes. Obviously, a network of local factors seems to influence the function of the oviduct, controlled by peripheral hormones. Cycle-dependent interactions between the growth factor, ECM and adrenergic systems will create the optimal environment for fertilization and early embryo development in the mammalian oviduct.