The involvement of the GHIGF-I axis in the regulation of secretory activity by bovine oviduct epithelial cells

The aim of this study was to investigate the role of the GHIGF-I system in the control of secretory activity by oviductal cells. The effects of GH (1, 10, 100 and 1000 ng/ml medium) on IGF-I production, as well as the action of GH and IGF-I (1, 10, 100, and 1000 ng/ml medium) on cAMP and prostaglandin F alpha (PGF) secretion by cultured bovine oviduct epithelial cells were studied. It was observed that GH at all doses tested significantly (p < 0.05) increased IGF-I secretion. Moreover, both GH and IGF-I significantly stimulated cAMP production by oviductal cells. On the other hand, PGF release was significantly (p < 0.05) inhibited by both GH and IGF-I at all concentrations tested. Our results demonstrate that: (1) oviductal cells can produce PGF alpha, cAMP and IGF-I, (2) production of PGF alpha is under inhibitory regulation by GH and IGF-I, (3) GHIGF can activate cAMP-dependent intracellular mechanisms, which might be the mediators of GHIGF-I action on oviductal cells. These observations confirm the involvement of GHIGF-I system in control of oviductal prostaglandin and cyclic nucleotide secretion.