title: Effect of growth hormone and inhibitors of protein kinase A on IGF-I, oxytocin and progesterone release by cultured bovine granulosa cells.
abstract: In our experiments we studied the action of GH on the release of nonapeptide, steroid hormones and growth factor, in bovine ovarian granulosa cells, as well as the role of cAMP-stimulated protein kinase A (PKA) in the mediation of these GH effects. For this purpose, the effects of exogenous bGH (0.001-10 mg/ml), PKA blockers KT5720 (100 ng/ml) and Rp-cAMPS (1 mmol), alone and in combination, on IGF-I, oxytocin and progesterone secretion were investigated. It was found that GH addition to culture medium strongly (p<0.05) stimulated IGF-I (at a concentration of 0.01-0.1 mgGH/ml medium), oxytocin (0.01-10 mgGH/ml) and progesterone (0.01-1 mgGH/ml medium) secretion into the culture medium. PKA blockers KT5720 and Rp-cAMPS given alone did not affect release of these substances. Rp-cAMPS partially prevented GH effect on IGF-I release, but enhanced GH action on progesterone output. KT5720 did not modify action of GH on oxytocin release. These observations confirm the involvement of GH in the control of IGF-I, oxytocin and progesterone release by bovine ovarian granulosa cells. Effects of PKA blocker on several GH-induced effects suggest that GH effects on IGF-I and progesterone, but not on oxytocin release may be partially mediated by the cAMP/PKA-dependent intracellular mechanisms.
authors.affiliation: Research Institute of Animal Production, Hlohovská 2, 949 92 Nitra, Slovakia. sirotkin@vuzv.sk.
authors.forename: A V
authors.initials: AV
authors.lastname: Sirotkin
authors.forename: A V
authors.initials: AV
authors.lastname: Makarevich
authors.forename: L
authors.initials: L
authors.lastname: Hetényi
mesh_terms: D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D017077:Culture Media, Conditioned; D000242:Cyclic AMP / Q000502:physiology; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D006107:Granulosa Cells / Q000187:drug effects / Q000378:metabolism*; D013006:Growth Hormone / Q000494:pharmacology*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D010121:Oxytocin / Q000378:metabolism*; D011374:Progesterone / Q000378:metabolism*
chemical_list: D017077:Culture Media, Conditioned; D004791:Enzyme Inhibitors; D011374:Progesterone; D010121:Oxytocin; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases