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de Bartolomeis A, De Simone G, De Prisco M, Barone A, Napoli R, Beguinot F, Billeci M, Fornaro M. Insulin effects on core neurotransmitter pathways involved in schizophrenia neurobiology: a meta-analysis of preclinical studies. Implications for the treatment. Mol Psychiatry 2023; 28:2811-2825. [PMID: 37085712 PMCID: PMC10615753 DOI: 10.1038/s41380-023-02065-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 03/28/2023] [Accepted: 03/31/2023] [Indexed: 04/23/2023]
Abstract
Impairment of insulin action and metabolic dysregulation have traditionally been associated with schizophrenia, although the molecular basis of such association remains still elusive. The present meta-analysis aims to assess the impact of insulin action manipulations (i.e., hyperinsulinemia, hypoinsulinemia, systemic or brain insulin resistance) on glutamatergic, dopaminergic, γ-aminobutyric acid (GABA)ergic, and serotonergic pathways in the central nervous system. More than one hundred outcomes, including transcript or protein levels, kinetic parameters, and other components of the neurotransmitter pathways, were collected from cultured cells, animals, or humans, and meta-analyzed by applying a random-effects model and adopting Hedges'g to compare means. Two hundred fifteen studies met the inclusion criteria, of which 180 entered the quantitative synthesis. Significant impairments in key regulators of synaptic plasticity processes were detected as the result of insulin handlings. Specifically, protein levels of N-methyl-D-aspartate receptor (NMDAR) subunits including type 2A (NR2A) (Hedges' g = -0.95, 95%C.I. = -1.50, -0.39; p = 0.001; I2 = 47.46%) and 2B (NR2B) (Hedges'g = -0.69, 95%C.I. = -1.35, -0.02; p = 0.043; I2 = 62.09%), and Postsynaptic density protein 95 (PSD-95) (Hedges'g = -0.91, 95%C.I. = -1.51, -0.32; p = 0.003; I2 = 77.81%) were found reduced in insulin-resistant animal models. Moreover, insulin-resistant animals showed significantly impaired dopamine transporter activity, whereas the dopamine D2 receptor mRNA expression (Hedges'g = 3.259; 95%C.I. = 0.497, 6.020; p = 0.021; I2 = 90.61%) increased under insulin deficiency conditions. Insulin action modulated glutamate and GABA release, as well as several enzymes involved in GABA and serotonin synthesis. These results suggest that brain neurotransmitter systems are susceptible to insulin signaling abnormalities, resembling the discrete psychotic disorders' neurobiology and possibly contributing to the development of neurobiological hallmarks of treatment-resistant schizophrenia.
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Affiliation(s)
- Andrea de Bartolomeis
- Section of Psychiatry, Laboratory of Molecular and Translational Psychiatry, Unit of Treatment-Resistant Psychiatric Disorders, Department of Neuroscience, Reproductive Sciences and Odontostomatology University of Naples "Federico II", School of Medicine, Via Pansini 5, 80131, Naples, Italy.
| | - Giuseppe De Simone
- Section of Psychiatry, Laboratory of Molecular and Translational Psychiatry, Unit of Treatment-Resistant Psychiatric Disorders, Department of Neuroscience, Reproductive Sciences and Odontostomatology University of Naples "Federico II", School of Medicine, Via Pansini 5, 80131, Naples, Italy
| | - Michele De Prisco
- Section of Psychiatry, Laboratory of Molecular and Translational Psychiatry, Unit of Treatment-Resistant Psychiatric Disorders, Department of Neuroscience, Reproductive Sciences and Odontostomatology University of Naples "Federico II", School of Medicine, Via Pansini 5, 80131, Naples, Italy
- Bipolar and Depressive Disorders Unit, Institute of Neuroscience, Hospital Clinic, University of Barcelona, IDIBAPS, CIBERSAM, 170 Villarroel st, 12-0, 08036, Barcelona, Catalonia, Spain
| | - Annarita Barone
- Section of Psychiatry, Laboratory of Molecular and Translational Psychiatry, Unit of Treatment-Resistant Psychiatric Disorders, Department of Neuroscience, Reproductive Sciences and Odontostomatology University of Naples "Federico II", School of Medicine, Via Pansini 5, 80131, Naples, Italy
| | - Raffaele Napoli
- Department of Translational Medical Sciences, University of Naples "Federico II", Via S. Pansini 5, 80131, Naples, Italy
- URT Genomic of Diabetes, Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy
| | - Francesco Beguinot
- Department of Translational Medical Sciences, University of Naples "Federico II", Via S. Pansini 5, 80131, Naples, Italy
- URT Genomic of Diabetes, Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy
| | - Martina Billeci
- Section of Psychiatry, Laboratory of Molecular and Translational Psychiatry, Unit of Treatment-Resistant Psychiatric Disorders, Department of Neuroscience, Reproductive Sciences and Odontostomatology University of Naples "Federico II", School of Medicine, Via Pansini 5, 80131, Naples, Italy
| | - Michele Fornaro
- Section of Psychiatry, Laboratory of Molecular and Translational Psychiatry, Unit of Treatment-Resistant Psychiatric Disorders, Department of Neuroscience, Reproductive Sciences and Odontostomatology University of Naples "Federico II", School of Medicine, Via Pansini 5, 80131, Naples, Italy
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Zhang X, Chen H, Li Y, Tang N, Chen D, Li Z. The insulin gene as an energy homeostasis biomarker in Yangtze sturgeon (Acipenser dabryanus). FISH PHYSIOLOGY AND BIOCHEMISTRY 2022; 48:693-705. [PMID: 35501527 DOI: 10.1007/s10695-022-01079-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Accepted: 04/18/2022] [Indexed: 06/14/2023]
Abstract
Insulin plays an important role in maintaining energy homeostasis and has the potential to be an indicator of energy homeostasis in the Yangtze sturgeon, Acipenser dabryanus. In this study, the Yangtze sturgeon insulin (Adinsulin) was cloned and characterized. To evaluate the possibility of insulin as an energy state assessment indicator, quantification real-time PCR (qRT-PCR) was used to evaluate expression changes in different tissues (the whole brain, esophagus, cardiac stomach, pyloric stomach, pyloric caeca, duodenum, valvula intestine, rectum, liver, pancreas, spleen, kidney, heart, muscle, gill and eye) from 6 fish (average weight 325.7 ± 22.3 g) and in three experiments including postprandial, fasting and re-feeding, and glucose tolerance treatment in which fish were divided into two groups including a group that administered a glucose solution (1 ul/g body weight) and another group that administered sterile water as control. In these three experiments, 6 fish were sampled, respectively, then been used to evaluate expression changes of insulin. All fish in feeding groups were fed in tanks (60.0 cm × 50.0 cm × 40.0 cm) with a commercial diet (crude protein ≥ 40%, crude fat ≥ 12%, coarse fiber ≤ 6%, crude ash ≤ 18%; TONGWEI CO., LTD, China) once a day at 16:00. The result showed that Adinsulin was highly expressed in the pancreas, which was the basis for the next experiment to use the pancreas as the test target. Adinsulin expression significantly increased 1 h after feeding and decreased rapidly after 3 h of feeding, but it was still significantly higher than that of the group without feeding (P < 0.01). Compared to the feeding group, the expression of Adinsulin was significantly reduced in the fasting group of 3 days (P < 0.01), 6 days (P < 0.01), 10 days (P < 0.05), 11 days (P < 0.05) and 13 days (P < 0.01) and was no significant difference in re-feeding for 1st day, 2nd day and 4th day, but there was difference between re-feeding group and fasting group. After glucose tolerance treatment, serum glucose levels increased significantly (P < 0.05), accompanied by a significant increase (P < 0.001) in insulin expression. This study result shows that insulin has the capacity to measure the energy homeostasis of Yangtze sturgeon. Further development of detection methods for sturgeon plasma or serum insulin will avoid slaughtering animals and is more practical in energy homeostasis assessment.
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Affiliation(s)
- Xin Zhang
- College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, 611130, China
| | - Hu Chen
- College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, 611130, China.
- Key Laboratory of Tropical Hydrobiology and Biotechnology of Hainan Province, Hainan Aquaculture Breeding Engineering Research Center, College of Marine Sciences, Hainan University, Hainan 5, Haikou, China.
| | - Ya Li
- College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, 611130, China
| | - Ni Tang
- College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, 611130, China
| | - Defang Chen
- College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, 611130, China
| | - Zhiqiong Li
- College of Animal Science and Technology, Sichuan Agricultural University, 211# Huimin Road, Chengdu, 611130, China.
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López-Patiño MA, Skrzynska AK, Naderi F, Mancera JM, Míguez JM, Martos-Sitcha JA. High Stocking Density and Food Deprivation Increase Brain Monoaminergic Activity in Gilthead Sea Bream ( Sparus aurata). Animals (Basel) 2021; 11:ani11061503. [PMID: 34067338 PMCID: PMC8224653 DOI: 10.3390/ani11061503] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 05/15/2021] [Accepted: 05/17/2021] [Indexed: 12/25/2022] Open
Abstract
In teleosts, brain monoamines (dopamine and serotonin) participate in the early response to different acute stressors. However, little is known regarding their role during chronic stress. In a 2 × 2 factorial design, the influence of a high stocking density (HSD) and/or food deprivation (FD) on the brain monoaminergic activity in gilthead sea bream (Sparus aurata) was evaluated. Following a 21-day experimental design, samples from the plasma and brain regions (telencephalon, hypothalamus, and optic tectum) were collected. The dopamine (DA), serotonin (5HT), and their main metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC) and 5 hydroxyindoleacetic acid (5HIAA), contents were HPLC-assessed in brain tissues, and the ratios DOPAC/DA and 5HIAA/5HT were calculated as indicators of enhanced monoaminergic activity. The plasma levels of cortisol and catecholamine were also evaluated. The cortisol levels increased in fish exposed to HSD and normally fed but, also, in all FD groups, whereas the NA levels decreased in LSD-FD animals. Within the brain, the dopaminergic and serotonergic activities in telencephalon and hypothalamus increased in fish subjected to HSD and in the telencephalon of LSD-FD fish. While DA (hypothalamus) and 5HT (telencephalon) increased in the animals submitted to a HSD, food-deprived fish did not show such an increase. Taken together, our results supported the hypothesis of brain monoaminergic activity participating in maintaining and orchestrating the endocrine response to chronic stress in fish.
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Affiliation(s)
- Marcos Antonio López-Patiño
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía and Centro de Investigación Mariña, Universidad de Vigo, 36310 Vigo, Spain; (M.A.L.-P.); (F.N.); (J.M.M.)
| | - Arleta Krystyna Skrzynska
- Department of Biology, Faculty of Marine and Environmental Sciences, Campus de Excelencia Internacional del Mar (CEI·MAR), Instituto Universitario de Investigación Marina (INMAR), University of Cádiz, 11519 Puerto Real, Spain; (A.K.S.); (J.M.M.)
| | - Fatemeh Naderi
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía and Centro de Investigación Mariña, Universidad de Vigo, 36310 Vigo, Spain; (M.A.L.-P.); (F.N.); (J.M.M.)
| | - Juan Miguel Mancera
- Department of Biology, Faculty of Marine and Environmental Sciences, Campus de Excelencia Internacional del Mar (CEI·MAR), Instituto Universitario de Investigación Marina (INMAR), University of Cádiz, 11519 Puerto Real, Spain; (A.K.S.); (J.M.M.)
| | - Jesús Manuel Míguez
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía and Centro de Investigación Mariña, Universidad de Vigo, 36310 Vigo, Spain; (M.A.L.-P.); (F.N.); (J.M.M.)
| | - Juan Antonio Martos-Sitcha
- Department of Biology, Faculty of Marine and Environmental Sciences, Campus de Excelencia Internacional del Mar (CEI·MAR), Instituto Universitario de Investigación Marina (INMAR), University of Cádiz, 11519 Puerto Real, Spain; (A.K.S.); (J.M.M.)
- Correspondence:
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Blanco AM, Bertucci JI, Soengas JL, Unniappan S. In vitro insulin treatment reverses changes elicited by nutrients in cellular metabolic processes that regulate food intake in fish. J Exp Biol 2020; 223:jeb213454. [PMID: 32179544 DOI: 10.1242/jeb.213454] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 03/09/2020] [Indexed: 12/13/2022]
Abstract
This research assessed the direct effects of insulin on nutrient-sensing mechanisms in the brain of rainbow trout (Oncorhynchus mykiss) using an in vitro approach. Cultured hypothalamus and hindbrain were exposed to 1 µmol l-1 insulin for 3 h, and signals involved in appetite regulation and nutrient-sensing mechanisms were measured. Additionally, the involvement of the phosphatidylinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway in the actions of insulin was studied by using the inhibitor wortmannin. Treatment with insulin alone did not elicit many changes in the appetite regulators and nutrient-sensing-related genes and enzymes tested in the hypothalamus and hindbrain. However, we found that, when insulin and nutrients were added together, insulin reversed most of the effects exerted by nutrients alone, suggesting that insulin changes responsiveness to nutrients at the central level. Effects reversed by insulin included expression levels of genes related to the sensing of both glucose (slc2a2, slc5a1, gck, pck1, pklr, g6pcb, gys1, tas1r3 and nr1h3 in the hindbrain, and slc2a2, pklr and pck1 in the hypothalamus) and fatty acid (cd36 in the hindbrain, and cd36 and acly in the hypothalamus). Nutrient-induced changes in the activity of Acly and Cpt-1 in the hindbrain and of Pepck, Acly, Fas and Hoad in the hypothalamus were also reversed by insulin. Most of the insulin effects disappeared in the presence of wortmannin, suggesting the PI3K/Akt pathway is a mediator of the effects of insulin reported here. This study adds new information to our knowledge of the mechanisms regulating nutrient sensing in fish.
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Affiliation(s)
- Ayelén M Blanco
- Laboratory of Integrative Neuroendocrinology, Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada, S7N 5B4
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía and Centro de Investigación Mariña-CIM, Universidade de Vigo, 36330 Vigo, Pontevedra, Spain
| | - Juan I Bertucci
- Laboratory of Integrative Neuroendocrinology, Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada, S7N 5B4
- Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada, S7N 5B3
| | - José L Soengas
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía and Centro de Investigación Mariña-CIM, Universidade de Vigo, 36330 Vigo, Pontevedra, Spain
| | - Suraj Unniappan
- Laboratory of Integrative Neuroendocrinology, Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada, S7N 5B4
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You JJ, Ren P, He S, Liang XF, Xiao QQ, Zhang YP. Histone Methylation of H3K4 Involved in the Anorexia of Carnivorous Mandarin Fish ( Siniperca chuatsi) After Feeding on a Carbohydrate-Rich Diet. Front Endocrinol (Lausanne) 2020; 11:323. [PMID: 32636801 PMCID: PMC7316955 DOI: 10.3389/fendo.2020.00323] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 04/27/2020] [Indexed: 12/15/2022] Open
Abstract
Food intake of carnivorous fish decreases after feeding on a carbohydrate-rich diet. However, the molecular mechanism underlying the anorexia caused by high-carbohydrate diets has remained elusive. We domesticated the mandarin fish to feed on carbohydrate-rich (8%) diets. After 61 days of feeding, several fish (Group A) fed well on artificial diets during the whole feeding period; the other fish (Group B) fed well on artificial diets at the beginning of the feeding period, with their food intake then decreasing to half (anorexia) and then to zero for 5 days; and, finally, a negative control (Group C) fed on live prey fish throughout the experimental process. The plasma glucose was significantly higher in the mandarin fish of Group B than in those of Group A, whereas levels of hepatic glycogen and plasma triglyceride were significantly lower. Using transcriptome sequencing, we investigated the differentially expressed genes between Groups A and B and excluded the genes that were not differentially expressed between Groups A and C. The activation of mTOR and Jak/STAT pathways were found in the mandarin fish with anorexia, which was consistent with the higher expression levels of pepck and pomc genes. We found a higher expression of histone methyltransferase setd1b gene and an increased histone H3 tri-methylated at lysine 4 (H3K4me3) in the fish of Group B. Furthermore, using ChIP assay and inhibitor treatment, we found that the up-regulated H3K4me3 could activate pepck expression, which might have contributed to the hyperglycemia and anorexia in the mandarin fish that fed on carbohydrate-rich diets. Our study initially indicated a link between histone methylation and pepck expression, which might be a novel regulatory mechanism of fish who are fed a carbohydrate-rich diet.
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Affiliation(s)
- Jun-Jie You
- College of Fisheries, Chinese Perch Research Center, Huazhong Agricultural University, Wuhan, China
- Innovation Base for Chinese Perch Breeding, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Wuhan, China
| | - Ping Ren
- College of Fisheries, Chinese Perch Research Center, Huazhong Agricultural University, Wuhan, China
- Innovation Base for Chinese Perch Breeding, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Wuhan, China
| | - Shan He
- College of Fisheries, Chinese Perch Research Center, Huazhong Agricultural University, Wuhan, China
- Innovation Base for Chinese Perch Breeding, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Wuhan, China
- *Correspondence: Shan He
| | - Xu-Fang Liang
- College of Fisheries, Chinese Perch Research Center, Huazhong Agricultural University, Wuhan, China
- Innovation Base for Chinese Perch Breeding, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Wuhan, China
| | - Qian-Qian Xiao
- College of Fisheries, Chinese Perch Research Center, Huazhong Agricultural University, Wuhan, China
- Innovation Base for Chinese Perch Breeding, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Wuhan, China
| | - Yan-Peng Zhang
- College of Fisheries, Chinese Perch Research Center, Huazhong Agricultural University, Wuhan, China
- Innovation Base for Chinese Perch Breeding, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Wuhan, China
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Mandic S, Volkoff H. The effects of fasting and appetite regulators on catecholamine and serotonin synthesis pathways in goldfish ( Carassius auratus ). Comp Biochem Physiol A Mol Integr Physiol 2018; 223:1-9. [DOI: 10.1016/j.cbpa.2018.04.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 04/09/2018] [Accepted: 04/27/2018] [Indexed: 10/17/2022]
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Castillo A, Alvarez A, Cuzon G, Suárez J, Gaxiola G. Glycemic response after glucose oral administration of wild juvenile red grouper Epinephelus morio fed two different diets. FISH PHYSIOLOGY AND BIOCHEMISTRY 2018; 44:219-226. [PMID: 28971287 DOI: 10.1007/s10695-017-0426-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 09/14/2017] [Indexed: 06/07/2023]
Abstract
Epinephelus morio is a large carnivorous species of the Caribbean Sea under reproduction in captivity and nutritional physiology. A diet with raw cornstarch (RCS) was compared to a basal diet without starch (basal) to measure plasma glucose, liver glycogen, and intermediary metabolism. Glucose level did not change (p > 0.05) whereas liver glycogen was significantly higher in fish fed the RCS diet (137.2 ± 14.5 mg g-1) than in fish fed the basal diet (87.4 ± 14.5 mg g-1). Oral glucose administration (170 mg glucose per 100 g body weight) yielded a slight change; two peaks of plasma glucose were recorded with basal (5.6 mM L-1) 2 h after oral administration and at 12 h (6.4 mM L-1). After 24 h, with 1.7 mM L-1, fish returned to initial stage (2.4 mM L-1). RCS diet produced the highest level (6.3 mM L-1) 2 h after oral administration; lowest level observed at 24 h after oral administration (1.0 mM L-1). A significant effect was detected with the presence or absence of dietary carbohydrates (CBH) on hepatic fructose 1,6-bisphosphatase and pyruvate kinase activity. Grouper used two strategies to maintain glucose homeostasis: CBH present in the diet oriented towards gluconeogenesis, whereas no dietary CBH enhanced glycolytic route to liberate glucose and increase liver glycogen.
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Affiliation(s)
- A Castillo
- Posgrado de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - A Alvarez
- DACBIOL, Universidad Juárez Autónoma de Tabasco, Mexico City, Mexico
| | - G Cuzon
- Unidad Multidisciplinaria de Docencia e Investigación de Sisal, Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - J Suárez
- Unidad Multidisciplinaria de Docencia e Investigación de Sisal, Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - G Gaxiola
- Unidad Multidisciplinaria de Docencia e Investigación de Sisal, Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico.
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Delgado MJ, Cerdá-Reverter JM, Soengas JL. Hypothalamic Integration of Metabolic, Endocrine, and Circadian Signals in Fish: Involvement in the Control of Food Intake. Front Neurosci 2017; 11:354. [PMID: 28694769 PMCID: PMC5483453 DOI: 10.3389/fnins.2017.00354] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2016] [Accepted: 06/07/2017] [Indexed: 12/12/2022] Open
Abstract
The regulation of food intake in fish is a complex process carried out through several different mechanisms in the central nervous system (CNS) with hypothalamus being the main regulatory center. As in mammals, a complex hypothalamic circuit including two populations of neurons: one co-expressing neuropeptide Y (NPY) and Agouti-related peptide (AgRP) and the second one population co-expressing pro-opiomelanocortin (POMC) and cocaine- and amphetamine-regulated transcript (CART) is involved in the integration of information relating to food intake control. The production and release of these peptides control food intake, and the production results from the integration of information of different nature such as levels of nutrients and hormones as well as circadian signals. The present review summarizes the knowledge and recent findings about the presence and functioning of these mechanisms in fish and their differences vs. the known mammalian model.
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Affiliation(s)
- María J. Delgado
- Departamento de Fisiología (Fisiología Animal II), Facultad de Biología, Universidad Complutense de MadridMadrid, Spain
| | - José M. Cerdá-Reverter
- Departamento de Fisiología de Peces y Biotecnología, Instituto de Acuicultura Torre de la Sal, Consejo Superior de Investigaciones CientíficasCastellón, Spain
| | - José L. Soengas
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de VigoVigo, Spain
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Conde-Sieira M, Soengas JL. Nutrient Sensing Systems in Fish: Impact on Food Intake Regulation and Energy Homeostasis. Front Neurosci 2017; 10:603. [PMID: 28111540 PMCID: PMC5216673 DOI: 10.3389/fnins.2016.00603] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 12/19/2016] [Indexed: 12/27/2022] Open
Abstract
Evidence obtained in recent years in a few species, especially rainbow trout, supports the presence in fish of nutrient sensing mechanisms. Glucosensing capacity is present in central (hypothalamus and hindbrain) and peripheral [liver, Brockmann bodies (BB, main accumulation of pancreatic endocrine cells in several fish species), and intestine] locations whereas fatty acid sensors seem to be present in hypothalamus, liver and BB. Glucose and fatty acid sensing capacities relate to food intake regulation and metabolism in fish. Hypothalamus is as a signaling integratory center in a way that detection of increased levels of nutrients result in food intake inhibition through changes in the expression of anorexigenic and orexigenic neuropeptides. Moreover, central nutrient sensing modulates functions in the periphery since they elicit changes in hepatic metabolism as well as in hormone secretion to counter-regulate changes in nutrient levels detected in the CNS. At peripheral level, the direct nutrient detection in liver has a crucial role in homeostatic control of glucose and fatty acid whereas in BB and intestine nutrient sensing is probably involved in regulation of hormone secretion from endocrine cells.
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Affiliation(s)
- Marta Conde-Sieira
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo Vigo, Spain
| | - José L Soengas
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo Vigo, Spain
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van de Pol I, Flik G, Gorissen M. Comparative Physiology of Energy Metabolism: Fishing for Endocrine Signals in the Early Vertebrate Pool. Front Endocrinol (Lausanne) 2017; 8:36. [PMID: 28303116 PMCID: PMC5332387 DOI: 10.3389/fendo.2017.00036] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 02/10/2017] [Indexed: 01/23/2023] Open
Abstract
Energy is the common currency of life. To guarantee a homeostatic supply of energy, multiple neuro-endocrine systems have evolved in vertebrates; systems that regulate food intake, metabolism, and distribution of energy. Even subtle (lasting) dysregulation of the delicate balance of energy intake and expenditure may result in severe pathologies. Feeding-related pathologies have fueled research on mammals, including of course the human species. The mechanisms regulating food intake and body mass are well-characterized in these vertebrates. The majority of animal life is ectothermic, only birds and mammals are endotherms. What can we learn from a (comparative) study on energy homeostasis in teleostean fishes, ectotherms, with a very different energy budget and expenditure? We present several adaptation strategies in fish. In recent years, the components that regulate food intake in fishes have been identified. Although there is homology of the major genetic machinery with mammals (i.e., there is a vertebrate blueprint), in many cases this does not imply analogy. Although both mammals and fish must gain their energy from food, the expenditure of the energy obtained is different. Mammals need to spend vast amounts of energy to maintain body temperature; fishes seem to utilize a broader metabolic range to their advantage. In this review, we briefly discuss ecto- and endothermy and their consequences for energy balance. Next, we argue that the evolution of endothermy and its (dis-)advantages may explain very different strategies in endocrine regulation of energy homeostasis among vertebrates. We follow a comparative and evolutionary line of thought: we discuss similarities and differences between fish and mammals. Moreover, given the extraordinary radiation of teleostean fishes (with an estimated number of 33,400 contemporary species, or over 50% of vertebrate life forms), we also compare strategies in energy homeostasis between teleostean species. We present recent developments in the field of (neuro)endocrine regulation of energy balance in teleosts, with a focus on leptin.
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Affiliation(s)
- Iris van de Pol
- Department of Animal Ecology and Physiology, Institute for Water and Wetland Research, Radboud University, Nijmegen, Netherlands
| | - Gert Flik
- Department of Animal Ecology and Physiology, Institute for Water and Wetland Research, Radboud University, Nijmegen, Netherlands
- *Correspondence: Gert Flik,
| | - Marnix Gorissen
- Department of Animal Ecology and Physiology, Institute for Water and Wetland Research, Radboud University, Nijmegen, Netherlands
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11
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Weber RA, Pérez Maceira JJ, Aldegunde MJ, Peleteiro JB, García Martín LO, Aldegunde M. Effects of acute handling stress on cerebral monoaminergic neurotransmitters in juvenile Senegalese sole Solea senegalensis. JOURNAL OF FISH BIOLOGY 2015; 87:1165-1175. [PMID: 26387448 DOI: 10.1111/jfb.12774] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Accepted: 07/20/2015] [Indexed: 06/05/2023]
Abstract
Juvenile Senegalese sole Solea senegalensis were subjected for short periods to two different types of handling-related stress: air exposure stress and net handling stress. The S. senegalensis were sacrificed 2 and 24 h after the stress events and the levels of serotonin (5-HT), noradrenaline (NA), dopamine (DA) and their respective major metabolites, 5-hydroxyindoleacetic acid (5-HIAA), 3-methoxy-4-hydroxyphenylglycol (MHPG) and 3,4-dihydroxyphenylacetic acid (DOPAC), were measured in three brain regions (telencephalon, hypothalamus and optic tectum) and compared with those in control, non-stressed S. senegalensis. Neither type of stress caused any significant alteration of serotoninergic activity (5-HIAA:5-HT ratio) or NA levels. Dopaminergic activity (DOPAC:DA ratio) was lower in stressed fish in all of the brain regions studied. For both air exposure stress and net handling stress, DA levels were significantly higher (P < 0.05) than in the control S. senegalensis. In addition, the higher DA levels after net handling stress were always significantly higher (P < 0.05) than those observed after acute air exposure stress, except in the telencephalon after 24 h. The significantly lower DOPAC:DA ratio (P < 0.05) in all of the brain regions studied was only observed in response to net handling stress.
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Affiliation(s)
- R A Weber
- Departamento de Fisiología (Laboratorio de Fisiología Animal), Facultad de Biología, Campus Vida s/n, Universidad de Santiago de Compostela, 15782, Santiago de Compostela, Spain
- Instituto de Acuicultura, Universidad de Santiago de Compostela, 15782, Santiago de Compostela, Spain
- Instituto Federal Catarinense, Campus Araquari, 89245-000, Araquari, Brazil
| | - J J Pérez Maceira
- Departamento de Fisiología (Laboratorio de Fisiología Animal), Facultad de Biología, Campus Vida s/n, Universidad de Santiago de Compostela, 15782, Santiago de Compostela, Spain
- Instituto de Acuicultura, Universidad de Santiago de Compostela, 15782, Santiago de Compostela, Spain
| | - M J Aldegunde
- Departamento de Fisiología (Laboratorio de Fisiología Animal), Facultad de Biología, Campus Vida s/n, Universidad de Santiago de Compostela, 15782, Santiago de Compostela, Spain
| | - J B Peleteiro
- Instituto Español de Oceanografía, Centro Oceanográfico de Vigo, Cabo Estai, Canido, 36200, Vigo, Spain
| | - L O García Martín
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Campus Vida s/n, Universidad de Santiago de Compostela, 15782, Santiago de Compostela, Spain
| | - M Aldegunde
- Departamento de Fisiología (Laboratorio de Fisiología Animal), Facultad de Biología, Campus Vida s/n, Universidad de Santiago de Compostela, 15782, Santiago de Compostela, Spain
- Instituto de Acuicultura, Universidad de Santiago de Compostela, 15782, Santiago de Compostela, Spain
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12
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Librán-Pérez M, Velasco C, Otero-Rodiño C, López-Patiño MA, Míguez JM, Soengas JL. Effects of insulin treatment on the response to oleate and octanoate of food intake and fatty acid-sensing systems in rainbow trout. Domest Anim Endocrinol 2015; 53:124-35. [PMID: 26226227 DOI: 10.1016/j.domaniend.2015.06.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 06/08/2015] [Accepted: 06/25/2015] [Indexed: 12/14/2022]
Abstract
We hypothesized that food intake and the response of fatty acid (FA)-sensing systems in hypothalamus, liver, and Brockmann bodies of rainbow trout to raised levels of oleate (OL) or octanoate (OCT) is modified by insulin treatment. To assess this hypothesis, 15 fish per group received intraperitoneally 10-mL/kg injection of saline solution alone (control), or containing insulin (2-mg bovine insulin/kg body mass), OL (300 μg/kg), OCT (300 μg/kg), insulin + OL, or insulin + OCT to be sampled 6 h later to assess parameters related to FA sensing. Our results suggest that the modulatory role of insulin on the responses of hypothalamic FA-sensing systems to changes in circulating levels of OL or OCT was of minor importance in contrast to the mammalian model. However, this is in contrast with the effects observed in another experiment assessing changes in food intake after similar treatments because insulin treatment enhanced the anorectic effects of FA alone, and the effect was especially relevant (P < 0.001) for OCT, in contrast with the mammalian model where this FA is not inducing an anorectic response. In liver and Brockmann bodies, insulin treatment enhanced the responses to OL or OCT treatment in parameters related to FA sensing. Therefore, we provide for the first time in fish, and in a non-mammalian vertebrate, evidence for the modulation of FA-sensing systems by insulin.
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Affiliation(s)
- M Librán-Pérez
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, 36310 Vigo, Spain
| | - C Velasco
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, 36310 Vigo, Spain
| | - C Otero-Rodiño
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, 36310 Vigo, Spain
| | - M A López-Patiño
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, 36310 Vigo, Spain
| | - J M Míguez
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, 36310 Vigo, Spain
| | - J L Soengas
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, 36310 Vigo, Spain.
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13
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Soengas JL. Contribution of glucose- and fatty acid sensing systems to the regulation of food intake in fish. A review. Gen Comp Endocrinol 2014; 205:36-48. [PMID: 24530522 DOI: 10.1016/j.ygcen.2014.01.015] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Revised: 01/13/2014] [Accepted: 01/28/2014] [Indexed: 01/01/2023]
Abstract
Food intake in fish is a complex process regulated through many different factors including abundance of energy and nutrients. In recent years, evidence have been obtained in several fishes, mainly in rainbow trout, regarding the presence and functioning in brain areas of metabolic sensors informing about changes in the levels of nutrients like glucose and fatty acids. The activity of these sensors relate to the control of food intake through changes in the expression of anorexigenic and orexigenic neuropeptides. The present review will provide a picture of the main results obtained to date in these studies, as well as perspectives for future research in the field.
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Affiliation(s)
- José L Soengas
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, Spain.
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14
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Pérez Maceira JJ, Mancebo MJ, Aldegunde M. The involvement of 5-HT-like receptors in the regulation of food intake in rainbow trout (Oncorhynchus mykiss). Comp Biochem Physiol C Toxicol Pharmacol 2014; 161:1-6. [PMID: 24365333 DOI: 10.1016/j.cbpc.2013.12.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Revised: 12/10/2013] [Accepted: 12/14/2013] [Indexed: 01/03/2023]
Abstract
It is known that in fish the serotonergic system is part of the neural network that controls feeding and that a pharmacologically induced increase in the brain 5-HT inhibits food intake. However, nothing is known about the 5-HT receptors involved in this inhibitory effect. In this study, we investigated the effects of several 5-HT1 and 5-HT2 receptor agonists on food intake in rainbow trout. In the first experiment, fish were injected i.p. or i.c.v. with two 5-HT1B receptor agonists, anpirtoline (2mg/kg, i.p.) and CP93129 (100 and 200μg/kg, i.c.v.). Neither of these treatments significantly altered food intake. In a second set of experiments, different groups of fish were injected i.p. (1mg/kg) or i.c.v. (30μg/kg) with the 5-HT1A receptor agonist 8-OH-DPAT. In both cases, administration of the 5-HT1A receptor agonist inhibited food intake. In a third set of experiments, we explored the effects of different 5-HT2 receptor agonists. Different groups of fish were injected i.p. or i.c.v. with the mixed 5-HT2B/2C agonist m-CPP (5mg/kg, i.p.), 5-HT2C agonist MK212 (60μg/kg, i.c.v.) and 5-HT2B agonist BW723C86 (50 and 100μg/kg, i.c.v.). Administration of the 5-HT2B/2C and 5HT2C receptor agonists significantly inhibited food intake. Administration of the lowest dose of the 5-HT2B receptor agonist did not have any significant effect, while administration of the highest dose induced a significant increase in food intake. Activation of the 5-HT1A-like (food intake inhibition) and 5-HT1B-like (no effect on food intake) receptors in the rainbow trout induced different effects on food intake from those observed in mammals. We conclude that in rainbow trout the anorexigenic actions of 5-HT are probably mediated by activation of 5-HT1A and 5-H2C-like receptors.
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Affiliation(s)
- Jorge J Pérez Maceira
- Laboratorio de Fisiología Animal (Instituto de Acuicultura), Facultad de Biología, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - María J Mancebo
- Laboratorio de Fisiología Animal (Instituto de Acuicultura), Facultad de Biología, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Manuel Aldegunde
- Laboratorio de Fisiología Animal (Instituto de Acuicultura), Facultad de Biología, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
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15
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Gesto M, Soengas JL, Rodríguez-Illamola A, Míguez JM. Arginine vasotocin treatment induces a stress response and exerts a potent anorexigenic effect in rainbow trout, Oncorhynchus mykiss. J Neuroendocrinol 2014; 26:89-99. [PMID: 24341528 DOI: 10.1111/jne.12126] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Revised: 11/28/2013] [Accepted: 12/12/2013] [Indexed: 12/16/2022]
Abstract
The peptide arginine vasotocin (AVT), homologous to mammalian arginine vasopressin, is involved in many aspects of fish physiology, such as osmoregulation, regulation of biological rhythms, reproduction, metabolism or responses to stress, and the modulation of social behaviours. Because a decrease in appetite is a general response to stress in fish and other vertebrates, we investigated the role of AVT as a possible food intake regulator in fish. We used i.c.v. injections for central administration of AVT to rainbow trout (Oncorhynchus mykiss). In a first experiment, we evaluated the temporal response of food intake after AVT treatment. In a second experiment, we investigated the effects of central AVT administration on the response of typical stress markers (plasma cortisol, glucose and lactate), as well as brain serotonergic, noradrenergic and dopaminergic activity. In addition, the mRNA levels of genes involved in food intake regulation [neuropetide Y, pro-opiomelanocortin (POMC), cocaine- and amphetamine-regulated transcript (CART) and corticotrophin-releasing factor (CRF)] and in CRF- (CRF-binding protein) and AVT-signalling (pro-VT and AVT receptor), were also assessed after AVT treatment. Our results showed that AVT is a potent anorexigenic factor in fish. Increases of plasma cortisol and glucose after AVT treatment strongly suggest that AVT administration induced a stress response and that AVT action was mediated by hypothalamic-pituitary-interrenal axis activation, which was also supported by the increase of the serotonergic activity in trout telencephalon and hypothalamus. The increased hypothalamic levels of POMC and CART suggest that these peptides might have a role in the anorexigenic action of AVT, whereas the involvement of CRF signalling is unclear.
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Affiliation(s)
- M Gesto
- Laboratorio de Fisiología animal, Departamento de Biología Funcional y CC. de la Salud, Facultad de Biología, Universidade de Vigo, Vigo, Spain
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16
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Mancebo MJ, Ceballos FC, Pérez-Maceira J, Aldegunde M. Hypothalamic neuropeptide Y (NPY) gene expression is not affected by central serotonin in the rainbow trout (Oncorhynchus mykiss). Comp Biochem Physiol A Mol Integr Physiol 2013; 166:186-90. [DOI: 10.1016/j.cbpa.2013.05.034] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 05/30/2013] [Accepted: 05/30/2013] [Indexed: 11/29/2022]
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17
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Renquist BJ, Zhang C, Williams SY, Cone RD. Development of an assay for high-throughput energy expenditure monitoring in the zebrafish. Zebrafish 2013; 10:343-52. [PMID: 23705823 DOI: 10.1089/zeb.2012.0841] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Energy homeostasis is maintained by balancing energy intake and expenditure. Many signals regulating energy intake are conserved between the human and teleost. However, before this work, there was no sensitive high-throughput system to monitor energy expenditure in the teleost. We exploit the nonfluorescent and fluorescent properties of resazurin and its reduced form resorufin (alamarBlue(®)) to monitor energy expenditure responses to drug application and genetic manipulation. We show that leptin, insulin, and alpha-melanocyte-stimulating hormone (α-MSH) increase energy expenditure dose dependently in the larval zebrafish. As previously established in the mouse, etomoxir, a carnitine palmitoyl transferase I inhibitor, blocks leptin-induced energy expenditure in the zebrafish. Metformin, the most commonly prescribed insulin sensitizer, increases the insulin-induced metabolic rate. Using genetic knockdown, we observed that α-MSH treatment increases the metabolic rate, as does knockdown of the melanocortin antagonist, agouti-related protein. The agouti-related protein and multiple melanocortin receptors are shown to be involved in these effects. These studies confirm that aspects of hormonal regulation of energy expenditure are conserved in the teleost, and suggest that this assay may provide a unique tool to perform in vivo screens for drugs or genes that affect the metabolic rate, including insulin or leptin sensitizers.
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18
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Pérez-Maceira JJ, Mancebo MJ, Aldegunde M. Serotonin-induced brain glycogenolysis in rainbow trout (Oncorhynchus mykiss). J Exp Biol 2012; 215:2969-79. [DOI: 10.1242/jeb.070649] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
In this study, we evaluated the serotonin-mediated control of cerebral glycogen levels in the rainbow trout, Oncorhynchus mykiss. Intracerebroventricular (i.c.v.) administration of serotonin (5-HT) to normoglycemic trout (time and dose response) decreased glycogen levels in the brain and increased brain glycogen phosphorylase activity (time response). In hypoglycemic fish (that had been fasted for 5 and 10 days), there was a time-dependent decrease in brain glycogen levels; under these conditions, i.c.v. administration of 5-HT also reduced the brain glycogen content in fish that had been fasted for 5 days. In fish with local cerebral hypoglycemia (induced by 2-DG administration), the glycogen levels decreased and, as above, i.c.v. administration of 5-HT also lowered the glycogen content. In hyperglycemic fish, 5-HT did not affect glycogen levels. Administration of receptor agonists 5-HT1A (8-OH-DPAT), 5-HT1B (anpirtoline and CP93129) or 5-HT2 (α-m-5-HT) decreased the brain glycogen levels. This effect was antagonized by the administration of receptor antagonists 5-HT1A (WAY100135 and NAN190), 5-HT1B (NAS181) and 5-HT2B/C (SB206553). Administration of the receptor agonists (±)-DOI (5-HT2A/2C), m-CPP (5-HT2B/2C), BW723C86 (5-HT2B) and WAY 161503 (5-HT2C) led to decreases in the levels of brain glycogen. We found that 5-HT is involved in the modulation of brain glycogen homeostasis in the rainbow trout, causing a glycogenolytic effect when fish are in a normoglycemic or hypoglycemic state, but not when they are in a hyperglycemic state. 5-HT1A, 5-HT1B, 5HT2B and 5-HT2C-like receptors appeared to be involved in the glycogenolytic action of 5-HT, although the effect mediated by 5-HT1A or 5-HT1B was apparently stronger.
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Affiliation(s)
- Jorge J. Pérez-Maceira
- Laboratorio de Fisiología Animal (Instituto de Acuicultura), Facultad de Biología, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - María J. Mancebo
- Laboratorio de Fisiología Animal (Instituto de Acuicultura), Facultad de Biología, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Manuel Aldegunde
- Laboratorio de Fisiología Animal (Instituto de Acuicultura), Facultad de Biología, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
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19
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Glucose metabolism in fish: a review. J Comp Physiol B 2012; 182:1015-45. [PMID: 22476584 DOI: 10.1007/s00360-012-0658-7] [Citation(s) in RCA: 376] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Revised: 03/06/2012] [Accepted: 03/10/2012] [Indexed: 02/07/2023]
Abstract
Teleost fishes represent a highly diverse group consisting of more than 20,000 species living across all aquatic environments. This group has significant economical, societal and environmental impacts, yet research efforts have concentrated primarily on salmonid and cyprinid species. This review examines carbohydrate/glucose metabolism and its regulation in these model species including the role of hormones and diet. Over the past decade, molecular tools have been used to address some of the downstream components of these processes and these are incorporated to better understand the roles played by carbohydrates and their regulatory paths. Glucose metabolism remains a contentious area as many fish species are traditionally considered glucose intolerant and, therefore, one might expect that the use and storage of glucose would be considered of minor importance. However, the actual picture is not so clear since the apparent intolerance of fish to carbohydrates is not evident in herbivorous and omnivorous species and even in carnivorous species, glucose is important for specific tissues and/or for specific activities. Thus, our aim is to up-date carbohydrate metabolism in fish, placing it to the context of these new experimental tools and its relationship to dietary intake. Finally, we suggest that new research directions ultimately will lead to a better understanding of these processes.
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20
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Weber RA, Maceira JJP, Mancebo MJ, Peleteiro JB, Martín LOG, Aldegunde M. Effects of acute exposure to exogenous ammonia on cerebral monoaminergic neurotransmitters in juvenile Solea senegalensis. ECOTOXICOLOGY (LONDON, ENGLAND) 2012; 21:362-369. [PMID: 21971970 DOI: 10.1007/s10646-011-0797-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 09/19/2011] [Indexed: 05/31/2023]
Abstract
The present study explored the potential role of brain catecholaminergic and serotoninergic systems as neuronal targets for the toxicological effects of acute ammonia exposure (0.28 mg l(-1) of un-ionized ammonia for 12 and 24 h) in juvenile sole (Solea senegalensis). In addition, plasma cortisol levels were measured. The results showed significant increases in their concentrations that were similar after 12 and 24 h of exposure. These data indicate that acute exposure (12 and 24 h) to ammonia initiates a typical stress response in the Senegalese sole, with stimulation of the hypothalamus-pituitary-interrenal axis. The concentrations of dopamine (DA), serotonin (5-hydroxytryptamine; 5-HT) and noradrenaline (NA), and their metabolites, 3, 4-dihydroxyphenylacetic acid (DOPAC) and 5-hydroxy-3-indoleacetic acid (5HIAA), were measured in the hypothalamus, telencephalon and optic tectum. The main changes induced by acute exposure to ammonia were decreases in the concentrations of 5-HT and DA, which were significant in most of the brain regions studied. The ratios of 5-HIAA/5-HT and DOPAC/DA increased in all regions and at all times studied, although in the case of the DOPAC/DA ratio, the increases were only significant in the hypothalamus (24 h exposure) and in the optic tectum (12 and 24 h exposure). These changes indicated that exposure to ammonia elicited time-dependent increases in serotoninergic and dopaminergic activity in the hypothalamus, telencephalon and optic tectum.
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Affiliation(s)
- R A Weber
- Departamento de Fisiología, Facultad de Biología, Universidad de Santiago de Compostela, Santiago de Compostela, Spain
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21
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Caruso MA, Sheridan MA. The expression of insulin and insulin receptor mRNAs is regulated by nutritional state and glucose in rainbow trout (Oncorhynchus mykiss). Gen Comp Endocrinol 2012; 175:321-8. [PMID: 22154645 DOI: 10.1016/j.ygcen.2011.11.029] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Revised: 11/16/2011] [Accepted: 11/18/2011] [Indexed: 11/16/2022]
Abstract
Many species of fish, including rainbow trout, possess multiple INS- and IR-encoding mRNAs. In this study, rainbow trout (Oncorhynchus mykiss) were used as a model to study the regulation of INS (INS1, INS2) and IR (IR1, IR2, IR3, and IR4) mRNA expression by nutritional state and glucose. In the nutritional state study, fish were either fed continuously, fasted (4 or 6 weeks), or fasted 4 weeks, then refed for 2 weeks. Nutritional state regulated INS and IR mRNA expression in a subtype- and tissue-specific manner. A 4-week fast reduced INS1 expression in endocrine pancreas (Brockmann body) and of INS1 and INS2 in brain, whereas a 6-week fast reduced the expression of both INS1 and INS2 in pancreas but only of INS1 in brain. Refeeding only restored INS2 levels in pancreas. In adipose tissue, by contrast, a 4-week fast increased INS1 expression, and a 6-week fast increased the expression of both INS1 and INS2. Nutritional state also modulated the pattern of IR mRNA expression. Fasting for 4 weeks resulted in no significant change in IR expression. Prolonged fasting (6 weeks) increased the expression of IR4 mRNA in the pancreas, adipose tissue, cardiac muscle, and gill; however, fasting decreased expression of IR3 mRNA in liver. Refeeding restored fasting-associated increases in IR4 expression in pancreas, adipose tissue, cardiac muscle, and gill, but had no effect on the fasting-associated decrease in IR3 expression in liver. Glucose differentially regulated the expression of INS and IR mRNAs in Brockmann bodies and liver pieces incubated in vitro, respectively. Low glucose (1 mM) reduced pancreatic expression of both INS1 and INS2 mRNAs compared to levels observed at 4 or 10 mM glucose. In the liver, IR1 and IR2 mRNA expression was insensitive to glucose concentration, whereas expression of IR3 and IR4 was attenuated at 1 and 10 mM compared to 4 mM glucose. These findings indicate that the pattern of INS and IR expression in selected tissues is regulated by nutritional state and glucose.
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Affiliation(s)
- Michael A Caruso
- Department of Biological Sciences, North Dakota State University, Fargo, ND 58108, USA
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22
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Caruso MA, Sheridan MA. New insights into the signaling system and function of insulin in fish. Gen Comp Endocrinol 2011; 173:227-47. [PMID: 21726560 DOI: 10.1016/j.ygcen.2011.06.014] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Revised: 06/08/2011] [Accepted: 06/14/2011] [Indexed: 12/11/2022]
Abstract
Fish have provided essential information about the structure, biosynthesis, evolution, and function of insulin (INS) as well as about the structure, evolution, and mechanism of action of insulin receptors (IR). INS, insulin-like growth factor (IGF)-1, and IGF-2 share a common ancestor; INS and a single IGF occur in Agnathans, whereas INS and distinct IGF-1 and IGF-2s appear in Chondrichthyes. Some but not all teleost fish possess multiple INS genes, but it is not clear if they arose from a common gene duplication event or from multiple separate gene duplications. INS is produced by the endocrine pancreas of fish as well as by several other tissues, including brain, pituitary, gastrointestinal tract, and adipose tissue. INS regulates various aspects of feeding, growth, development, and intermediary metabolism in fish. The actions of INS are mediated through the insulin receptor (IR), a member of the receptor tyrosine kinase family. IRs are widely distributed in peripheral tissues of fish, and multiple IR subtypes that derive from distinct mRNAs have been described. The IRs of fish link to several cellular effector systems, including the ERK and IRS-PI3k-Akt pathways. The diverse effects of INS can be modulated by altering the production and release of INS as well as by adjusting the production/surface expression of IR. The diverse actions of INS in fish as well as the diverse nature of the neural, hormonal, and environmental factors known to affect the INS signaling system reflects the various life history patterns that have evolved to enable fish to occupy a wide range of aquatic habitats.
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Affiliation(s)
- Michael A Caruso
- Department of Biological Sciences, North Dakota State University, Fargo, ND 58108, USA
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23
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Polakof S, Mommsen TP, Soengas JL. Glucosensing and glucose homeostasis: from fish to mammals. Comp Biochem Physiol B Biochem Mol Biol 2011; 160:123-49. [PMID: 21871969 DOI: 10.1016/j.cbpb.2011.07.006] [Citation(s) in RCA: 205] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2011] [Revised: 07/20/2011] [Accepted: 07/22/2011] [Indexed: 12/16/2022]
Abstract
This review is focused on two topics related to glucose in vertebrates. In a first section devoted to glucose homeostasis we describe how glucose levels fluctuate and are regulated in different classes of vertebrates. The detection of these fluctuations is essential for homeostasis and for other physiological processes such as regulation of food intake. The capacity of that detection is known as glucosensing, and the different mechanisms through which it occurs are known as glucosensors. Different glucosensor mechanisms have been demonstrated in different tissues and organs of rodents and humans whereas the information obtained for other vertebrates is scarce. In the second section of the review we describe the present knowledge regarding glucosensor mechanisms in different groups of vertebrates, with special emphasis in fish.
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Affiliation(s)
- Sergio Polakof
- INRA, UMR, UNH, CRNH Auvergne, Clermont-Ferrand, France.
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Subhedar N, Barsagade VG, Singru PS, Thim L, Clausen JT. Cocaine- and amphetamine-regulated transcript peptide (CART) in the telencephalon of the catfish, Clarias gariepinus: distribution and response to fasting, 2-deoxy-D-glucose, glucose, insulin, and leptin treatments. J Comp Neurol 2011; 519:1281-300. [PMID: 21452197 DOI: 10.1002/cne.22569] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The cocaine- and amphetamine-regulated transcript peptide (CART)-containing system in the forebrain of Clarias gariepinus was studied with immunocytochemistry. While the immunoreactivity was prominently seen in the neurons of the entopeduncular nucleus (EN) located in the ventral telencephalon, CART-immunoreactive fibers were widely distributed in the dorsal and ventral telencephalon. In view of the established role of CART in energy metabolism, we investigated the response of the CART immunoreactive system to positive and negative nutritional conditions. Neurons of the EN and fibers in the different areas of the telencephalon showed significant reduction in CART immunoreactivity following 48 hours food deprivation, or 2 hours following intracranial administration of 2-deoxy-D-glucose (2DG, 100 ng/g body weight, a metabolic antagonist of glucose). However, intracranial injection of glucose (100 ng/g body weight) resulted in a distinct increase in CART immunoreactivity in these components. In mammals, insulin and leptin have been recognized as adiposity agents that convey peripheral energy status-related information to brain. Intracranial administration of insulin (3 mU/fish) and leptin (10 ng/g body weight) significantly increased CART immunoreactivity in the EN neurons and in the fiber network within 2 hours. Superfusion of the EN-containing tissue fragments in the medium enriched in glucose, insulin, or leptin evoked a significant increase in CART immunoreactivity in the EN neurons, but 2DG reduced the immunoreactivity. We suggest that CART-containing neurons of the EN, and fibers in the telencephalon, may process the energy status-related information and contribute to satiety.
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Affiliation(s)
- Nishikant Subhedar
- Indian Institute of Science Education and Research, Sutarwadi, Pashan, Pune, India.
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Volkoff H, Hoskins LJ, Tuziak SM. Influence of intrinsic signals and environmental cues on the endocrine control of feeding in fish: potential application in aquaculture. Gen Comp Endocrinol 2010; 167:352-9. [PMID: 19735660 DOI: 10.1016/j.ygcen.2009.09.001] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2009] [Revised: 08/30/2009] [Accepted: 09/02/2009] [Indexed: 01/05/2023]
Abstract
Optimization of food consumption and ultimately growth are major concerns for aquaculture. In fish, food intake is regulated by several hormones produced by both brain and peripheral tissues. Changes in feeding behavior and appetite usually occur through the modulation of the gene expression and/or action of these appetite-regulating hormones and can be due not only to variations in intrinsic factors such as nutritional/metabolic or reproductive status, but also to changes in environmental factors, such as temperature and photoperiod. In addition, the gene expression and/or plasma levels of appetite-regulating hormones might also display daily as well as circannual (seasonal) rhythms. Despite recent advances, our current understanding of the regulation of feeding in fish is still limited. We give here a brief overview of our current knowledge of the endocrine regulation of feeding in fish and describe how a better understanding of appetite-related hormones in fish might lead to the development of sustainable aquaculture.
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Affiliation(s)
- Hélène Volkoff
- Department of Biology, Memorial University of Newfoundland, St. John's, NL, Canada.
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Tubío RIC, Pérez-Maceira J, Aldegunde M. Homeostasis of glucose in the rainbow trout (Oncorhynchus mykiss Walbaum): the role of serotonin. J Exp Biol 2010; 213:1813-21. [DOI: 10.1242/jeb.035444] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
In this study, we evaluated, for the first time, the 5-HT (serotonin)-mediated control of glucose homeostasis in the rainbow trout Oncorhynchus mykiss. Intraperitoneal administration of 5-HT increased plasma levels of glucose, adrenaline and noradrenaline. By contrast, intracerebroventricular administration of 5-HT did not cause any significant variation in plasma levels of glucose. The release of endogenous 5-HT following intraperitoneal administration of d-fenfluramine led to a significant increase in plasma levels of glucose and adrenaline. Intraperitoneal administration of (1) MIAN (a 5-HT2 receptor antagonist) did not block either the hyperglycaemic action or the increase in plasma levels of adrenaline induced by 5-HT, but did block the increase in plasma levels of noradrenaline, and (2) 5-CT (a 5-HT1 agonist) increased the plasma levels of glucose and of adrenaline, without altering those of noradrenaline. Administration of TFMPP (a 5-HT1B agonist) did not increase the plasma levels of glucose, and the hyperglycaemic action of 5-HT was not blocked by antagonists of 5-HT1A (WAY 100635), 5-HT1D (BRL 15572), 5-HT2B (SB 204741) or 5-HT7 (pimozide) receptors. It was demonstrated that, in rainbow trout, peripheral 5-HT, but not brain 5-HT intervenes in the modulation of glucose homeostasis with a hyperglycaemic effect. This effect is associated with the release of adrenaline and activation of 5-HT1-like receptors. As far as could be determined in the present study, these 5-HT1-like receptors are unrelated to either the 5-HT1A, 5-HT1B or 5-HT1D receptor subtypes of mammals. The 5-HT2-type receptors may mediate the release of noradrenaline, but not of adrenaline, and furthermore, do not appear to play an important role in the hyperglycaemic effect exerted by 5-HT.
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Affiliation(s)
- Rosa I. Caamaño Tubío
- Laboratorio de Fisiología Animal (Instituto de Acuicultura), Facultad de Biología, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Jorge Pérez-Maceira
- Laboratorio de Fisiología Animal (Instituto de Acuicultura), Facultad de Biología, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Manuel Aldegunde
- Laboratorio de Fisiología Animal (Instituto de Acuicultura), Facultad de Biología, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
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Polakof S, Alvarez R, Soengas JL. Gut glucose metabolism in rainbow trout: implications in glucose homeostasis and glucosensing capacity. Am J Physiol Regul Integr Comp Physiol 2010; 299:R19-32. [PMID: 20357022 DOI: 10.1152/ajpregu.00005.2010] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The main objective of the present study was to evaluate the relative contribution of the intestine to glucose homeostasis in rainbow trout. In a first set of in vivo experiments trout were subjected to oral glucose treatments alone or in combination with insulin injections to assess changes in glucose-related enzymes activities, metabolite levels, and mRNA levels. Rainbow trout gut displays an important glucose metabolism that includes the ability to store glucose as glycogen (mostly in the muscle layers) and a large capacity to oxidize glucose. This constitutes a surprising result for a carnivorous fish. In a second set of in vivo experiments, trout received an oral amino acid solution alone or in combination with insulin injection to determine whether other factors besides fasting could regulate gluconeogenesis in intestine. The results confirm the absence of regulation of gluconeogenesis in trout gut, which does not respond to hormones, glucose, lactate, or amino acid changes, either in vivo or in vitro. We also fully characterized gut glucose metabolism in vitro. We observed that a large amount of glucose is oxidized to lactate, supporting the importance of glucose in gut metabolism. Moreover, we corroborated the minor actions of insulin in trout gut, whereas other hormones such as glucagon-like peptide-1 and C-peptide appear to be major hormonal regulators of glucose metabolism in fish gut. Finally, we obtained the first evidence for the existence of a glucosensing mechanism in the midgut of this carnivorous species.
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Affiliation(s)
- Sergio Polakof
- Laboratorio de Fisioloxía Animal, Facultade de Bioloxía, Edificio de Ciencias Experimentais, Universidade de Vigo, Vigo, Spain.
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The gastrointestinal tract as an endocrine/neuroendocrine/paracrine organ: organization, chemical messengers and physiological targets. FISH PHYSIOLOGY 2010. [DOI: 10.1016/s1546-5098(10)03007-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Barreiro-Iglesias A, Aldegunde M, Anadón R, Rodicio MC. Extensive presence of serotonergic cells and fibers in the peripheral nervous system of lampreys. J Comp Neurol 2009; 512:478-99. [DOI: 10.1002/cne.21914] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Polakof S, Míguez JM, Soengas JL. Changes in food intake and glucosensing function of hypothalamus and hindbrain in rainbow trout subjected to hyperglycemic or hypoglycemic conditions. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2008; 194:829-39. [PMID: 18663455 DOI: 10.1007/s00359-008-0354-y] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2008] [Revised: 06/13/2008] [Accepted: 07/15/2008] [Indexed: 01/10/2023]
Abstract
To evaluate the possible role of glucose in the control of food intake (FI) in fish and the involvement of glucosensing system in that role, we have subjected rainbow trout (via intraperitoneal injections) to control, hyperglycemic (500 mg kg(-1) glucose body mass) or hypoglycemic (4 mg kg(-1) bovine insulin) conditions for 10 days. The experimental design was appropriate since hypoglycemia and hyperglycemia were observed the first 5 days after treatment and changes observed in metabolic parameters in liver were similar to those of fish literature. Hyperglycemic conditions elicited small changes in FI accompanied by increased glucose and glycogen levels, glucokinase (GK) activity and glycolytic potential in hypothalamus and hindbrain. In contrast, hypoglycemic conditions elicited a marked increase in FI accompanied by decreased glucose and glycogen levels and GK activity in the same brain regions whereas both regions displayed different responses in glycolytic potential. These results allow us to hypothesize that, despite the relative intolerance to glucose of carnivorous fish, changes in plasma glucose levels in rainbow trout detected by glucosensing areas in brain regions (hypothalamus and hindbrain) are integrated in those or near areas eliciting a response in FI, which was more important under hypoglycemic than under hyperglycemic conditions.
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Affiliation(s)
- Sergio Polakof
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, Edificio de Ciencias Experimentais, 36310, Vigo, Spain
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Abstract
Feeding behavior is a complex behavior that is closely associated with food intake. Fish have a wide variety of feeding habits and feeding patterns making them good experimental models for the study of the regulation of feeding behavior. The aquatic nature of fish often creates challenges in the study of feeding behavior and different approaches have been used by researchers, including field studies, observations of free-living animals, and laboratory experiments. Feeding behavior is regulated by a number of environmental factors and also by complex homeostatic mechanisms that involve central and peripheral hormonal factors as well as metabolites. This review summarizes our current knowledge on the control of feeding behavior of fish, with emphasis on the methodology used and on the endocrine and metabolic regulation of feeding.
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Affiliation(s)
- Helene Volkoff
- Department of Biology, Memorial University of Newfoundland, St. John's, Newfoundland NL A1B 3X9, Canada.
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Albalat A, Saera-Vila A, Capilla E, Gutiérrez J, Pérez-Sánchez J, Navarro I. Insulin regulation of lipoprotein lipase (LPL) activity and expression in gilthead sea bream (Sparus aurata). Comp Biochem Physiol B Biochem Mol Biol 2007; 148:151-9. [PMID: 17600746 DOI: 10.1016/j.cbpb.2007.05.004] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2007] [Revised: 05/10/2007] [Accepted: 05/11/2007] [Indexed: 11/20/2022]
Abstract
Lipoprotein lipase (LPL) is a key enzyme in lipoprotein metabolism by virtue of its capacity to hydrolyze triglycerides circulating in the form of lipoprotein particles. Here we analyzed the fasting effects of LPL in gilthead sea bream (Sparus aurata) and also present the first study in fish of the role of insulin as a potential modulator of both LPL activity and expression. Fasting for 2 weeks provoked a clear decrease in adipose tissue LPL activity, concomitant with lower levels of plasma insulin, while no effects were observed in red muscle. To elucidate the specific role of insulin, increases of plasma insulin were experimentally induced by arginine and insulin injections. However, arginine predominantly stimulated glucagon over insulin secretion in this fish species while LPL activity did not change significantly in adipose tissue. Instead, insulin administration induced an increase in adipose tissue LPL activity 3 h after the injection, whereas LPL activity in red muscle was not affected. Changes in LPL activity were accompanied by an increase in LPL mRNA levels in the adipose tissue of insulin-injected gilthead sea bream, although changes in LPL expression were delayed in time with respect to variations in LPL activity. Finally, LPL mRNA levels in red muscle were similar between control and insulin-injected gilthead sea bream, suggesting that insulin does not play a direct role in the regulation of LPL in this tissue. The current study shows that LPL activity is regulated by nutritional condition and underscores the importance of insulin as a modulator of LPL activity and expression in the adipose tissue of gilthead sea bream.
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Affiliation(s)
- A Albalat
- Departament de Fisiologia, Facultat de Biologia, Universitat de Barcelona, Avda. Diagonal 645, Barcelona, E-0807, Spain
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Nelson LE, Sheridan MA. Gastroenteropancreatic hormones and metabolism in fish. Gen Comp Endocrinol 2006; 148:116-24. [PMID: 16516213 DOI: 10.1016/j.ygcen.2006.01.011] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2005] [Revised: 01/20/2006] [Accepted: 01/21/2006] [Indexed: 11/26/2022]
Abstract
Metabolism of vertebrates integrates a vast array of systems and processes, including the pursuit and capture of food, feeding and digestion of ingested food, absorption and transport of nutrients, assimilation, partitioning and utilization of energy, and the processing and elimination of wastes. Fish, which are the most diverse group of vertebrates and occupy a wide range of habitats and display numerous life history patterns, have proven to be important models for the study of the structure, biosynthesis, evolution, and function of gastroenteropancreatic (GEP) hormones. Food intake is promoted by galanin, neuropeptide Y, and pancreatic polypeptide (PP), while cholecystokinin (CCK) and glucagon-like peptide-1 (GLP-1) inhibit food intake. Digestion of ingested food is facilitated by CCK, PP, and secretin by coordinating gastrointestinal tract motility and regulation of exocrine secretion. Somatostatins (SS), on the other hand, generally inhibit exocrine secretions. Insulin facilitates assimilation by promoting the uptake of nutrient molecules (e.g., glucose, amino acids, and fatty acids) into cells. Insulin also is generally anabolic and stimulates the synthesis and deposition of energy reserves (e.g., glycogen, triacylglycerol) as well as of proteins, thereby facilitating organismal growth. Insulin-like growth factors (e.g., IGF-1) also promote cell proliferation and organismal growth. Breakdown and mobilization of stored energy reserves is stimulated by glucagon, GLP-1, and SS. Somatostatins also affect metabolism and reproduction via their effects on the thyroid axis as well as growth via effects on growth hormone (GH) release and perhaps directly via modulation of GH sensitivity. Studies in fish have revealed that GEP hormones play an important role in coordinating the various aspects of metabolism with each other and with the physiological and developmental status of the animal as well as with the environment.
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Affiliation(s)
- Laura E Nelson
- Department of Biological Sciences, North Dakota State University, Fargo, ND 58105, USA
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Aldegunde M, Mancebo M. Effects of neuropeptide Y on food intake and brain biogenic amines in the rainbow trout (Oncorhynchus mykiss). Peptides 2006; 27:719-27. [PMID: 16253390 DOI: 10.1016/j.peptides.2005.09.014] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2005] [Revised: 09/20/2005] [Accepted: 09/23/2005] [Indexed: 10/25/2022]
Abstract
Neuropeptide Y (NPY) is one of the most potent stimulants of food intake in mammals, but very little is known about NPY actions in fish. The present study investigated the role of NPY in food intake in the rainbow trout (Oncorhynchus mykiss). Food intake was monitored at different times after intracerebroventricular administration of porcine NPY (4 or 8 microg). Both doses significantly increased food intake at 2 and 3 h, and this effect was dose-dependent. However, 50 h after administration of NPY, food intake was significantly lower than in control fish, and cumulative food intake had returned to levels similar to those seen in the control group. The NPY antagonist (D-Tyr27,36, D-Thr32)-NPY (10 microg) inhibited food intake 2 h after icv administration, but did not block the orexigenic effect of NPY when administered jointly with 4 microg NPY. To identify the NPY receptor subtypes involved in the effects of NPY on food intake, we studied the effects of the Y1 receptor agonist (Leu31, Pro34)-NPY (4 microg), the Y2 receptor agonist NPY(3-36) (4 microg), and the highly specific Y5 receptor agonist (cPP(1-7), NPY19-23, Ala31, Aib32, Gln34)-hPP (4 microg). Short-term (2 h) food intake was moderately stimulated by the Y1 agonist, more strongly stimulated by the Y2 agonist, and unaffected by the Y5 agonist. We found that administration of NPY (8 microg icv) had no effect on aminergic systems in several brain regions 2 and 50 h after NPY administration. These results indicate that NPY stimulates feeding in the rainbow trout, and suggest that this effect is cooperatively mediated by Y2- and Y1-like NPY receptors, not by Y5-like receptors.
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Affiliation(s)
- M Aldegunde
- Laboratorio de Fisioloxía Animal, Dpto. de Fisioloxía, Facultade de Bioloxía, Universidade de Santiago de Compostela, E-15782 Santiago de Compostela, Spain.
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