Subdiaphragmatic vagus nerve activity and hepatic venous glucose are differentially regulated by the central actions of insulin in Wistar and SHR

Autor(es)

Ribeiro, Izabela Martina R. ; Ferreira-Neto, Hildebrando C. ; Antunes, Vagner R.

• Tipo de documento: Artigo Científico
• Fonte: PHYSIOLOGICAL REPORTS; v. 3, n. 5 MAY 2015.
• Citações Web of Science: 4

Resumo

Glucose is the most important energy substrate for the maintenance of tissues function. The liver plays an essential role in the control of glucose production, since it is able to synthesize, store, and release glucose into the circulation under different situations. Hormones like insulin and catecholamines influence hepatic glucose production (HGP), but little is known about the role of the central actions of physiological doses of insulin in modulating HGP via the autonomic nervous system in nonanesthetized rats especially in SHR where we see a high degree of insulin resistance and metabolic dysfunction. Wistar and SHR received ICV injection of insulin (100 nU/mu L) and hepatic venous glucose concentration (HVGC) was monitored for 30 min, as an indirect measure of HGP. At 10 min after insulin injection, HVGC decreased by 27% in Wistar rats, with a negligible change (3%) in SHR. Pretreatment with atropine totally blocked the reduction in HVGC, while pretreatment with propranolol and phentolamine induced a decrease of 8% in HVGC after ICV insulin injection in Wistar. Intracarotid infusion of insulin caused a significant increase in subdiaphragmatic vagus nerve (SVN) activity in Wistar (12 +/- 2%), with negligible effects on the lumbar splanchnic sympathetic nerve (LSSN) activity (-6 +/- 3%). No change was observed in SVN (-2 +/- 2%) and LSSN activities (2 +/- 3%) in SHR after ICA insulin infusion. Taken together, these results show, in nonanesthetized animals, the importance of the parasympathetic nervous system in controlling HVGC, and subdiaphragmatic nerve activity following central administration of insulin; a mechanism that is impaired in the SHR. (AU)

• Processo FAPESP: 07/04085-0 - Análise funcional de genes relacionados à hipertensão neurogênica
• Beneficiário: Vagner Roberto Antunes
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 09/13047-0 - Papel do sistema nervoso autonômico sobre a produção hepática de glicose via ação central de insulina em animais hipertensos
• Beneficiário: Izabela Martina Ramos Ribeiro de Toledo
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 10/05037-1 - Papel dos receptores purinérgicos do núcleo paraventricular do hipotálamo na hipertensão neurogênica
• Beneficiário: Hildebrando Candido Ferreira Neto
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 13/06206-0 - Estudo da expressão gênica de neuropeptídeos e mediadores inflamatórios em núcleos do eixo hipotálamo-tronco cerebral envolvidos no controle neural da pressão arterial de animais submetidos a dieta obesogênica
• Beneficiário: Vagner Roberto Antunes
• Modalidade de apoio: Auxílio à Pesquisa - Regular