title: In vitro evidence supports the presence of glucokinase-independent glucosensing mechanisms in hypothalamus and hindbrain of rainbow trout.
abstract: We previously obtained evidence in rainbow trout for the presence and response to changes in circulating levels of glucose (induced by intraperitoneal hypoglycaemic and hyperglycaemic treatments) of glucosensing mechanisms based on liver X receptor (LXR), mitochondrial production of reactive oxygen species (ROS) leading to increased expression of uncoupling protein 2 (UCP2), and sweet taste receptor in the hypothalamus, and on sodium/glucose co-transporter 1 (SGLT-1) in hindbrain. However, these effects of glucose might be indirect. Therefore, we evaluated the response of parameters related to these glucosensing mechanisms in a first experiment using pooled sections of hypothalamus and hindbrain incubated for 6 h at 15°C in modified Hanks' medium containing 2, 4 or 8 mmol l(-1) d-glucose. The responses observed in some cases were consistent with glucosensing capacity. In a second experiment, pooled sections of hypothalamus and hindbrain were incubated for 6 h at 15°C in modified Hanks' medium with 8 mmol l(-1) d-glucose alone (control) or containing 1 mmol l(-1) phloridzin (SGLT-1 antagonist), 20 µmol l(-1) genipin (UCP2 inhibitor), 1 µmol l(-1) trolox (ROS scavenger), 100 µmol l(-1) bezafibrate (T1R3 inhibitor) and 50 µmol l(-1) geranyl-geranyl pyrophosphate (LXR inhibitor). The response observed in the presence of these specific inhibitors/antagonists further supports the proposal that critical components of the different glucosensing mechanisms are functioning in rainbow trout hypothalamus and hindbrain.
authors.affiliation: Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, Vigo E-36310, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Otero-Rodiño
authors.affiliation: Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, Vigo E-36310, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Velasco
authors.affiliation: Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, Vigo E-36310, Spain.
authors.forename: Rosa
authors.initials: R
authors.lastname: Álvarez-Otero
authors.affiliation: Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, Vigo E-36310, Spain.
authors.forename: Marcos A
authors.initials: MA
authors.lastname: López-Patiño
authors.affiliation: Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, Vigo E-36310, Spain.
authors.forename: Jesús M
authors.initials: JM
authors.lastname: Míguez
authors.affiliation: Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, Vigo E-36310, Spain jsoengas@uvigo.es.
authors.forename: José L
authors.identifier: 0000-0002-6847-3993
authors.initials: JL
authors.lastname: Soengas
mesh_terms: D000818:Animals; D005941:Glucokinase / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism*; D007031:Hypothalamus / Q000378:metabolism*; D000071518:Liver X Receptors / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism; D017686:Oncorhynchus mykiss / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism; D012249:Rhombencephalon / Q000378:metabolism*; D051269:Sodium-Glucose Transporter 1 / Q000235:genetics / Q000378:metabolism
chemical_list: D000071518:Liver X Receptors; D012333:RNA, Messenger; D043562:Receptors, G-Protein-Coupled; D051269:Sodium-Glucose Transporter 1; C431926:taste receptors, type 1; D005941:Glucokinase; D005947:Glucose
keywords: Glucosensing; Hindbrain; Hypothalamus; Rainbow trout