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 (Bos taurus) were examined duri ng the various cycle stages using a combination of cell biology- and molecu lar-biology techniques [reverse transcriptase polymerase chain reaction (RT -PCR), RNase protection assay (RPA), immunohistology, radioimmunoassay (RIA ), receptor-assay, cell culture]. In detail the oviductal expression of the following components was analysed: fibroblast (FGF) and vascular-endotheli al (VEGF) growth factor systems; extracellular matrix (ECM) enzymes such as plasminogen-activator (PA) and matrixmetalloproteases (MMP), adrenergic re ceptors (alpha 2 and beta 2 AdR) and an anti-oxidative protein (glutathionp eroxidase = GPx). A specific cycle-dependant and local regulation of the ex pression could be demonstrated, not only for growth factors such as FGF1 an d VEGF but also for ECM components. Remarkable progesterone-dependent incre ases of the beta 2 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 t he growth factor, ECM and adrenergic systems will create the optimal enviro nment for fertilization and early embryo development in the mammalian ovidu ct.