Control of ovarian steroidogenesis by insulin-like peptides in the blowfly (Phormia regina)
| Autor: | E E Büllesbach, Elisabeth Vanhems, I. Rondot, G Maniere, F Gautron, Jean-Paul Delbecque |
|---|---|
| Přispěvatelé: | Développement et Communication Chimique chez les Insectes ( DCCI ), Centre National de la Recherche Scientifique ( CNRS ) -Université de Bourgogne ( UB ) -AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement, Delon, Viviane |
| Rok vydání: | 2004 |
| Předmět: |
medicine.medical_specialty
Time Factors Endocrinology Diabetes and Metabolism medicine.medical_treatment Morpholines Endogeny blowfly chemistry.chemical_compound Phosphatidylinositol 3-Kinases Endocrinology Organ Culture Techniques Internal medicine Control medicine Animals Insulin Phosphatidylinositol PI3K/AKT/mTOR pathway Phosphoinositide-3 Kinase Inhibitors biology Diptera Neuropeptides Ovary Estrogens Phormia regina biology.organism_classification insulin-like peptides In vitro Stimulation Chemical Insulin receptor chemistry Chromones Insect Hormones biology.protein Cattle Female ovarian steroidogenesis Signal transduction |
| Zdroj: | Journal of Endocrinology Journal of Endocrinology, BioScientifica, 2004, 181 (?), pp.147-56 |
| ISSN: | 0022-0795 1479-6805 |
| Popis: | 0022–0795/04/0181–147; This study investigated the ability of insulin and of insect insulin-like peptides (ILPs) to stimulate ovarian steroidogenesis in the blowfly Phormia regina. Bovine insulin was active on ovaries isolated in vitro, which showed an age-dependent sensitivity; this peptide progressively stimulated steroidogenesis in ovaries isolated from the third day after adult molt, but not in younger ones, and had maximal activity after the fifth day. This stimulatory effect was observed equally from females reared in the presence or in the absence of males, excluding a regulatory effect of mating. The mode of action of insulin in blowflies did not involve cAMP, but triggered a specific and well-conserved transduction cascade. In particular, a peroxovanadium compound, known to activate specifically the insulin receptor in mammals, also stimulated blowfly ovarian steroidogenesis in vitro. Conversely, chemicals known to inhibit the mammalian insulin receptor or downstream elements of its signaling pathway, such as LY294002, an inhibitor of phosphatidylinositol 3-kinase (PI3K), were able to prevent the steroidogenic action of bovine insulin on fly ovaries. Extracts from the median neurosecretory cells (MNCs) of blowfly brains, which are known to contain endogenous ILPs, stimulated ovarian steroidogenesis very efficiently and were also sensitive to inhibition by LY294002. These experiments indicated the involvement of PI3K in the mode of action of MNC extracts and substantiated that their endogenous ILPs are involved in the regulation of ovarian steroidogenesis. This conclusion was corroborated by the effects of synthetic bombyxin II, an ILP originating from silkworm MNCs, which also stimulated steroidogenesis in isolated blowfly ovaries. Altogether, these data suggest that insulinlike neurohormones from MNCs play a crucial role as steroidogenic gonadotropins in female flies |
| Databáze: | OpenAIRE |
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