Ingman, W.Owens, P.Armstrong, D.2006-06-242006-06-242000Molecular and Cellular Endocrinology, 2000; 164(1-2):53-580303-72071872-8057http://hdl.handle.net/2440/8387Website © 2000 Ingenta. Article copyright remains with the publisher, society or author(s) as specified within the articleInhibition of insulin-like growth factor (IGF)-I induced DNA synthesis in bovine oocyte-cumulus complexes (OCCs) caused by follicle-stimulating hormone (FSH) has been linked to changes in the extracellular matrix which do not occur in mural granulosa cells (MGCs). We investigated regulation by IGF-I and FSH of secreted and extracellular matrix entrapped IGF-binding proteins. OCCs and MGCs from bovine ovaries were cultured in media supplemented with IGF-I and FSH for 24 h. Culture media and extracellular matrix were analysed for IGF-binding proteins by Western ligand blot and immunoblot and found to contain principally IGFBP-3 and -5. The combined treatment of IGF-I and FSH increased the concentration of IGFBP-3 in OCC and MGC conditioned media by 4- and 6-fold, respectively. Treatment of OCCs and not MGCs with IGF-I and FSH together increased extracellular matrix IGFBP-5 by 2.5-fold. The differential regulation of extracellular matrix IGFBP-5 in OCCs compared to MGCs suggest involvement of changes in the extracellular matrix brought about by IGF-I and FSH in overall regulation of IGF-I in the ovarian follicle.enInsulin-like growth factor binding proteinExtracellular matrixOocyteCumulus oophorusGranulosa cellsFollicle-stimulating hormoneJournal article000100110210.1016/S0303-7207(00)00240-90000888484000062-s2.0-003469099263391Ingman, W. [0000-0003-3116-2902]