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Lopes FNC, da Cunha NV, de Campos BH, Fattori V, Panis C, Cecchini R, Verri WA, Pinge-Filho P, Martins-Pinge MC. Antioxidant therapy reverses sympathetic dysfunction, oxidative stress, and hypertension in male hyperadipose rats. Life Sci 2022; 295:120405. [PMID: 35181311 DOI: 10.1016/j.lfs.2022.120405] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 02/08/2022] [Accepted: 02/11/2022] [Indexed: 10/19/2022]
Abstract
AIMS The rostral ventrolateral medulla (RVLM) is the main sympathetic output of the central nervous system to control blood pressure. Reportedly, reactive oxygen species (ROS) can increase arterial pressure, leading to hypertension. As ROS increase the sympathetic tone in RVLM and obese animals present grater oxidative stress, it would be important to note this relationship. MAIN METHODS Therefore, we evaluated the systemic and central effects (in the RVLM) of vitamin C (vit C, an antioxidant) on the redox balance and cardiovascular and autonomic profiles in hyperadipose male rats. We also evaluated the neurotransmission by L-glutamate (L-glu) and vit C in the RVLM of awake hyperadipose rats. KEY FINDINGS Our study confirmed that hyperadipose rats were hypertensive and tachycardic, presented increased sympathetic and decreased parasympathetic modulation of the heart, and had increased plasma lipoperoxidation compared with the control rats (CTR). Oral vitamin C treatment reverted cardiovascular, autonomic, and plasma redox dysfunction. Hyperadipose rats presented a higher blood pressure increase after L-glu microinjection and a lower response to vit C in the RVLM compared with the CTR group. Biochemical analysis of redox balance in RVLM punches showed that hyperadipose rats have increased NBT and T-BARS, and after treatment with vit C, the oxidative profile decreased. The antioxidative activity of vit C reduced the amount of ROS in the RVLM area that might have resulted in lowered blood pressure and sympathetic modulation. SIGNIFICANCE Our data suggest central and peripheral benefits of vit C treatment on cardiovascular, autonomic, and oxidative dysfunctions in hyperadipose animals.
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Affiliation(s)
- Fernanda Novi Cortegoso Lopes
- Departament of Physiological Sciences, Center of Biological Sciences, State University of Londrina, Londrina, PR, Brazil
| | - Natália Veronez da Cunha
- Departament of Physiological Sciences, Center of Biological Sciences, State University of Londrina, Londrina, PR, Brazil
| | - Blenda Hyedra de Campos
- Departament of Physiological Sciences, Center of Biological Sciences, State University of Londrina, Londrina, PR, Brazil
| | - Victor Fattori
- Departament of Pathological Sciences, Center of Biological Sciences, State University of Londrina, Londrina, PR, Brazil
| | - Carolina Panis
- Tumor Biology Laboratory, Health Sciences Center, State University of Western Paraná, Francisco Beltrão, Paraná, Brazil
| | - Rubens Cecchini
- Departament of Pathological Sciences, Center of Biological Sciences, State University of Londrina, Londrina, PR, Brazil
| | - Waldiceu Aparecido Verri
- Departament of Pathological Sciences, Center of Biological Sciences, State University of Londrina, Londrina, PR, Brazil
| | - Phileno Pinge-Filho
- Departament of Pathological Sciences, Center of Biological Sciences, State University of Londrina, Londrina, PR, Brazil
| | - Marli Cardoso Martins-Pinge
- Departament of Physiological Sciences, Center of Biological Sciences, State University of Londrina, Londrina, PR, Brazil.
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Maternal soy protein isolate diet during lactation programs deleterious effects on hepatic lipid metabolism, atherogenic indices, and function of adrenal in adult rat offspring. J Dev Orig Health Dis 2021; 13:177-186. [PMID: 33975670 DOI: 10.1017/s2040174421000180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The benefits of consuming soy and its protein have been reported in many studies. However, its phytoestrogen content raises concerns about consumption during lactation and gestation We therefore examined the effects of soybean or soy protein isolate on the parameters-related cardiovascular pathophysiology in lactating mothers and their offsprings at weaning and adulthood. Lactating rats were divided: casein control (C); soy protein isolate (SPI); and soybean (S). At weaning, half of the litter received commercial ration up to 150 days. The levels of 17-β-estradiol and superoxide dismutase were low in the S mothers. For the SPI mothers, we observed a reduction of thiobarbituric acid reactive substances (TBARS). At weaning, atherogenic indices [1 = total cholesterol (TC)/HDL; 2 = LDL/HDL; 3 = TC-HDL/HDL)] decreased in the S and SPI offsprings compared to the casein control group; TBARS and antioxidant enzymes increased in the S offspring, while reduced/oxidized glutathione ratio increased in the SPI offspring, indicating lower oxidative stress. In adulthood, the SPI offspring showed an increase in liver cholesterol and atherogenic index 1 and 3 (vs. C and S) and 2 (vs. S). In addition, we found a decrease in catecholamines in the adrenal medulla and an increase in caffeine-stimulated secretion, but tyrosine hydroxylase expression remained constant. Maternal consumption of SPI during lactation worsened atherogenic indices of the offsprings in adulthood, which was associated with increased liver cholesterol and decreased catecholamines in the adrenal medulla. Soy consumption had no consistent long-term effects on the evaluated parameters compared to casein consumption. The data suggest that the consumption of SPI during lactation should be done with caution.
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Stefanovic B, Spasojevic N, Jovanovic P, Dronjak S. Melatonin treatment affects changes in adrenal gene expression of catecholamine biosynthesizing enzymes and norepinephrine transporter in the rat model of chronic-stress-induced depression. Can J Physiol Pharmacol 2019; 97:685-690. [PMID: 30773040 DOI: 10.1139/cjpp-2018-0612] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
This study investigated the effects of melatonin treatment on adrenal catecholamine content, synthesis, uptake, and vesicular transport induced by the chronic unpredictable mild stress (CUMS) model of depression in rats. This entailed quantifying the norepinephrine, epinephrine, mRNA, and protein levels of tyrosine hydroxylase (TH), dopamine-β-hydroxylase (DBH), phenylethanolamine N-methyltransferase (PNMT), norepinephrine transporter (NET), and vesicular monoamine transporter 2 (VMAT2) in the adrenal medulla. CUMS caused a significant depletion of norepinephrine stores and protein levels of TH, DBH, and NET, whereas the gene expression of PNMT was increased. It was observed that melatonin treatment in the CUMS rats prevented the stress-induced decrease in norepinephrine content and the protein expression of TH, DBH, and NET in the adrenal medulla of chronically stressed rats. The present study demonstrates the stimulatory effect of melatonin on adrenomedullary synthesis, the uptake and content of catecholamine in the rat model of chronic stress-induced depression.
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Affiliation(s)
- Bojana Stefanovic
- a Department of Molecular Biology and Endocrinology, Institute of Nuclear Sciences "Vinca", University of Belgrade, Belgrade, Serbia
| | - Natasa Spasojevic
- a Department of Molecular Biology and Endocrinology, Institute of Nuclear Sciences "Vinca", University of Belgrade, Belgrade, Serbia
| | - Predrag Jovanovic
- a Department of Molecular Biology and Endocrinology, Institute of Nuclear Sciences "Vinca", University of Belgrade, Belgrade, Serbia.,b CEDARS-SINAI, Center for Neural Science and Medicine, 8700 Beverly Blvd., Los Angeles, CA 90048, USA
| | - Sladjana Dronjak
- a Department of Molecular Biology and Endocrinology, Institute of Nuclear Sciences "Vinca", University of Belgrade, Belgrade, Serbia
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Sanches JR, França LM, Chagas VT, Gaspar RS, Dos Santos KA, Gonçalves LM, Sloboda DM, Holloway AC, Dutra RP, Carneiro EM, Cappelli APG, Paes AMDA. Polyphenol-Rich Extract of Syzygium cumini Leaf Dually Improves Peripheral Insulin Sensitivity and Pancreatic Islet Function in Monosodium L-Glutamate-Induced Obese Rats. Front Pharmacol 2016; 7:48. [PMID: 27014062 PMCID: PMC4785152 DOI: 10.3389/fphar.2016.00048] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2015] [Accepted: 02/22/2016] [Indexed: 12/23/2022] Open
Abstract
Syzygium cumini (L.) Skeels (Myrtaceae) has been traditionally used to treat a number of illnesses. Ethnopharmacological studies have particularly addressed antidiabetic and metabolic-related effects of extracts prepared from its different parts, especially seed, and pulp-fruit, however. there is a lack of studies on phytochemical profile and biological properties of its leaf. As there is considerable interest in bioactive compounds to treat metabolic syndrome and its clustered risk factors, we sought to characterize the metabolic effects of hydroethanolic extract of S. cumini leaf (HESc) on lean and monosodium L-glutamate (MSG)-induced obese rats. HPLC-MS/MS characterization of the HESc polyphenolic profile, at 254 nm, identified 15 compounds pertaining to hydrolysable tannin and flavanol subclasses. At 60 days of age, both groups were randomly assigned to receive HESc (500 mg/kg) or vehicle for 30 days. At the end of treatment, obese+HESc exhibited significantly lower body weight gain, body mass index, and white adipose tissue mass, compared to obese rats receiving vehicle. Obese rats treated with HESc showed a twofold increase in lipolytic activity in the periepididymal fat pad, as well as, brought triglyceride levels in serum, liver and skeletal muscle back to levels close those found in lean animals. Furthermore, HESc also improved hyperinsulinemia and insulin resistance in obese+HESc rats, which resulted in partial reversal of glucose intolerance, as compared to obese rats. HESc had no effect in lean rats. Assessment of ex vivo glucose-stimulated insulin secretion showed HESc potentiated pancreatic function in islets isolated from both lean and obese rats treated with HESc. In addition, HESc (10–1000 μg/mL) increased glucose stimulated insulin secretion from both isolated rat islets and INS-1E β-cells. These data demonstrate that S. cumini leaf improved peripheral insulin sensitivity via stimulating/modulating β-cell insulin release, which was associated with improvements in metabolic outcomes in MSG-induced obese rats.
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Affiliation(s)
- Jonas R Sanches
- Laboratory of Experimental Physiology, Department of Physiological Sciences, Federal University of Maranhão São Luís, Brazil
| | - Lucas M França
- Laboratory of Experimental Physiology, Department of Physiological Sciences, Federal University of Maranhão São Luís, Brazil
| | - Vinicyus T Chagas
- Laboratory of Experimental Physiology, Department of Physiological Sciences, Federal University of Maranhão São Luís, Brazil
| | - Renato S Gaspar
- Laboratory of Experimental Physiology, Department of Physiological Sciences, Federal University of Maranhão São Luís, Brazil
| | - Kayque A Dos Santos
- Laboratory of Experimental Physiology, Department of Physiological Sciences, Federal University of Maranhão São Luís, Brazil
| | - Luciana M Gonçalves
- Laboratory of Endocrine Pancreas and Metabolism, Department of Estructural and Functional Biology, Institute of Biology, State University of Campinas Campinas, Brazil
| | - Deborah M Sloboda
- Departments of Biochemistry, Pediatrics and Obstetrics and Gynecology, McMaster University Hamilton, ON, Canada
| | - Alison C Holloway
- Department of Obstetrics and Gynecology, McMaster University Hamilton, ON, Canada
| | - Richard P Dutra
- Social, Health and Technological Sciences Center, Federal University of Maranhão Imperatriz, Brazil
| | - Everardo M Carneiro
- Laboratory of Endocrine Pancreas and Metabolism, Department of Estructural and Functional Biology, Institute of Biology, State University of Campinas Campinas, Brazil
| | - Ana Paula G Cappelli
- Laboratory of Experimental Physiology, Department of Physiological Sciences, Federal University of Maranhão São Luís, Brazil
| | - Antonio Marcus de A Paes
- Laboratory of Experimental Physiology, Department of Physiological Sciences, Federal University of Maranhão São Luís, Brazil
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Quines CB, Rosa SG, Velasquez D, Da Rocha JT, Neto JSS, Nogueira CW. Diphenyl diselenide elicits antidepressant-like activity in rats exposed to monosodium glutamate: A contribution of serotonin uptake and Na(+), K(+)-ATPase activity. Behav Brain Res 2015; 301:161-7. [PMID: 26738966 DOI: 10.1016/j.bbr.2015.12.038] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 12/19/2015] [Accepted: 12/22/2015] [Indexed: 12/30/2022]
Abstract
Depression is a disorder with symptoms manifested at the psychological, behavioral and physiological levels. Monosodium glutamate (MSG) is the most widely used additive in the food industry; however, some adverse effects induced by this additive have been demonstrated in experimental animals and humans, including functional and behavioral alterations. The aim of this study was to investigate the possible antidepressant-like effect of diphenyl diselenide (PhSe)2, an organoselenium compound with pharmacological properties already documented, in the depressive-like behavior induced by MSG in rats. Male and female newborn Wistar rats were divided in control and MSG groups, which received, respectively, a daily subcutaneous injection of saline (0.9%) or MSG (4g/kg/day) from the 1st to 5th postnatal day. At 60th day of life, animals received (PhSe)2 (10mg/kg, intragastrically) 25min before spontaneous locomotor and forced swimming tests (FST). The cerebral cortices of rats were removed to determine [(3)H] serotonin (5-HT) uptake and Na(+), K(+)-ATPase activity. A single administration of (PhSe)2 was effective against locomotor hyperactivity caused by MSG in rats. (PhSe)2 treatment protected against the increase in the immobility time and a decrease in the latency for the first episode of immobility in the FST induced by MSG. Furthermore, (PhSe)2 reduced the [(3)H] 5-HT uptake and restored Na(+), K(+)-ATPase activity altered by MSG. In the present study a single administration of (PhSe)2 elicited an antidepressant-like effect and decrease the synaptosomal [(3)H] 5-HT uptake and an increase in the Na(+), K(+)-ATPase activity in MSG-treated rats.
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Affiliation(s)
- Caroline B Quines
- Laboratório de Síntese, Reatividade e Avaliação Farmacológica e Toxicológica de Organocalcogênios, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, CEP 97105-900 RS, Brazil
| | - Suzan G Rosa
- Laboratório de Síntese, Reatividade e Avaliação Farmacológica e Toxicológica de Organocalcogênios, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, CEP 97105-900 RS, Brazil
| | - Daniela Velasquez
- Laboratório de Síntese, Reatividade e Avaliação Farmacológica e Toxicológica de Organocalcogênios, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, CEP 97105-900 RS, Brazil
| | - Juliana T Da Rocha
- Laboratório de Síntese, Reatividade e Avaliação Farmacológica e Toxicológica de Organocalcogênios, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, CEP 97105-900 RS, Brazil
| | - José S S Neto
- Laboratório de Síntese, Reatividade e Avaliação Farmacológica e Toxicológica de Organocalcogênios, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, CEP 97105-900 RS, Brazil
| | - Cristina W Nogueira
- Laboratório de Síntese, Reatividade e Avaliação Farmacológica e Toxicológica de Organocalcogênios, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, CEP 97105-900 RS, Brazil.
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Effects of Orlistat and herbal mixture extract on brain, testes functions and oxidative stress biomarkers in a rat model of high fat diet. BENI-SUEF UNIVERSITY JOURNAL OF BASIC AND APPLIED SCIENCES 2014. [DOI: 10.1016/j.bjbas.2014.05.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
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Quines CB, Rosa SG, Da Rocha JT, Gai BM, Bortolatto CF, Duarte MMMF, Nogueira CW. Monosodium glutamate, a food additive, induces depressive-like and anxiogenic-like behaviors in young rats. Life Sci 2014; 107:27-31. [PMID: 24802127 DOI: 10.1016/j.lfs.2014.04.032] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Revised: 04/22/2014] [Accepted: 04/23/2014] [Indexed: 12/16/2022]
Abstract
UNLABELLED Monosodium glutamate (MSG) has been the target of research due to its toxicological effects. AIMS We investigated the depressive- and anxiogenic-like behaviors in rats exposed to neonatal subcutaneous injection of MSG. The involvement of the serotonergic system, by measuring [(3)H] serotonin (5-HT) uptake in cerebral cortices, and the hypothalamic pituitary adrenal (HPA) axis, by determining serum adrenocorticotropic hormone (ACTH) and corticosterone levels, was also examined. MATERIALS AND METHODS Male and female newborn Wistar rats were divided into control and MSG groups, which received, respectively, a daily subcutaneous injection of saline (0.9%) or MSG (4 g/kg/day) from the 1st to 5th postnatal day. The behavioral tests [spontaneous locomotor activity, contextual fear conditioning, and forced swimming test (FST)] were performed from the 60th to 64th postnatal day. MSG-treated animals showed alteration in the spontaneous locomotor activity, an increase in the number of fecal pellets and the number of animal's vocalizations and urine occurrence, and a decrease in the grooming time. KEY FINDINGS The MSG exposure increased the immobility time in the FST and the freezing reaction in the contextual fear conditioning. Additionally, MSG treatment increased the [(3)H]5-HT uptake in the cerebral cortices of rats and induced a deregulation of HPA axis function (by increasing serum ACTH and corticosterone levels). SIGNIFICANCE In conclusion MSG-treated rats are more susceptible to develop anxiogenic- and depressive-like behaviors, which could be related to a dysfunction in the serotonergic system.
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Affiliation(s)
- Caroline B Quines
- Laboratório de Síntese, Reatividade e Avaliação Farmacológica e Toxicológica de Organocalcogênios, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, CEP 97105-900, Rio Grande do Sul, Brazil
| | - Suzan G Rosa
- Laboratório de Síntese, Reatividade e Avaliação Farmacológica e Toxicológica de Organocalcogênios, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, CEP 97105-900, Rio Grande do Sul, Brazil
| | - Juliana T Da Rocha
- Laboratório de Síntese, Reatividade e Avaliação Farmacológica e Toxicológica de Organocalcogênios, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, CEP 97105-900, Rio Grande do Sul, Brazil
| | - Bibiana M Gai
- Laboratório de Síntese, Reatividade e Avaliação Farmacológica e Toxicológica de Organocalcogênios, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, CEP 97105-900, Rio Grande do Sul, Brazil
| | - Cristiani F Bortolatto
- Laboratório de Síntese, Reatividade e Avaliação Farmacológica e Toxicológica de Organocalcogênios, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, CEP 97105-900, Rio Grande do Sul, Brazil
| | - Marta Maria M F Duarte
- Departamento de Ciências da Saúde, Universidade Luterana do Brasil, Santa Maria, Rio Grande do Sul, Brazil
| | - Cristina W Nogueira
- Laboratório de Síntese, Reatividade e Avaliação Farmacológica e Toxicológica de Organocalcogênios, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, CEP 97105-900, Rio Grande do Sul, Brazil.
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Impaired muscarinic type 3 (M3) receptor/PKC and PKA pathways in islets from MSG-obese rats. Mol Biol Rep 2013; 40:4521-8. [DOI: 10.1007/s11033-013-2546-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Accepted: 04/29/2013] [Indexed: 10/26/2022]
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Karlen-Amarante M, da Cunha NV, de Andrade O, de Souza HCD, Martins-Pinge MC. Altered baroreflex and autonomic modulation in monosodium glutamate-induced hyperadipose rats. Metabolism 2012; 61:1435-42. [PMID: 22554831 DOI: 10.1016/j.metabol.2012.03.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Revised: 03/08/2012] [Accepted: 03/09/2012] [Indexed: 11/25/2022]
Abstract
We aimed to examine the cardiovascular function by tonic and baroreflex alterations in obese rats induced by monosodium glutamate (MSG). Neonatal male Wistar rats were injected with MSG (4 mg/g body weight) or equimolar saline (control, C). At 90 days, all rats were anesthetized for catheterization of the femoral artery for mean arterial pressure (MAP) and heart rate (HR) recordings in the conscious state. After baseline, we performed IV treatment with hexamethonium (25 mg/kg), or atropine (1 mg/kg) or propranolol (3 mg/kg). We also performed the spectral analysis of heart rate variability (HRV) and baroreflex sensitivity. Baseline comparison showed that obese rats are hypertensive compared with control (C=110±2 mmHg; MSG=: 123±3 mmHg, P<0.05). After ganglionic blockade with hexamethonium the differences in MAP between control and obese rats disappeared. Beta adrenergic blockade with propranolol induced a greater decrease in heart rate compared with control. The analysis of HRV showed that obese rats have increased modulation by both components of the autonomic nervous system compared with control rats. The baroreflex gain showed increased sensitivity for the parasympathetic component in the obese rats (C=-2.41±0.25; MSG=-3.34±0.23 bpm/mmHg) compared with control. Our data suggest that both components of autonomic cardiac tonus and the parasympathetic component of the baroreflex sensitivity are increased in the MSG obese rat. It is possible that the parasympathetic alterations observed in these MSG obese rats may have originated from central areas of cardiovascular control.
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Conceição EPS, Moura EG, Trevenzoli IH, Peixoto-Silva N, Pinheiro CR, Younes-Rapozo V, Oliveira E, Lisboa PC. Neonatal overfeeding causes higher adrenal catecholamine content and basal secretion and liver dysfunction in adult rats. Eur J Nutr 2012; 52:1393-404. [DOI: 10.1007/s00394-012-0448-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Accepted: 09/13/2012] [Indexed: 12/12/2022]
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COX-2 inhibition does not reverse the increased sympathetic modulation in MSG obese rats. Auton Neurosci 2011; 165:201-4. [DOI: 10.1016/j.autneu.2011.07.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Revised: 07/13/2011] [Accepted: 07/15/2011] [Indexed: 11/23/2022]
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Lobato NS, Filgueira FP, Akamine EH, Davel APC, Rossoni LV, Tostes RC, Carvalho MHC, Fortes ZB. Obesity induced by neonatal treatment with monosodium glutamate impairs microvascular reactivity in adult rats: role of NO and prostanoids. Nutr Metab Cardiovasc Dis 2011; 21:808-816. [PMID: 20554176 DOI: 10.1016/j.numecd.2010.02.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2009] [Revised: 02/05/2010] [Accepted: 02/08/2010] [Indexed: 01/23/2023]
Abstract
BACKGROUND AND AIM given that obesity is an independent risk factor for the development of cardiovascular diseases we decided to investigate the mechanisms involved in microvascular dysfunction using a monosodium glutamate (MSG)-induced model of obesity, which allows us to work on both normotensive and normoglycemic conditions. METHODS AND RESULTS Male offspring of Wistar rats received MSG from the second to the sixth day after birth. Sixteen-week-old MSG rats displayed higher Lee index, fat accumulation, dyslipidemia and insulin resistance, with no alteration in glycemia and blood pressure. The effect of norepinephrine (NE), which was increased in MSG rats, was potentiated by L-nitro arginine methyl ester (L-NAME) or tetraethylammonium (TEA) and was reversed by indomethacin and NS-398. Sensitivity to acetylcholine (ACh), which was reduced in MSG rats, was further impaired by L-NAME or TEA, and was corrected by indomethacin, NS-398 and tetrahydrobiopterin (BH4). MSG rats displayed increased endothelium-independent relaxation to sodium nitroprusside. A reduced prostacyclin/tromboxane ratio was found in the mesenteric beds of MSG rats. Mesenteric arterioles of MSG rats also displayed reduced nitric oxide (NO) production along with increased reactive oxygen species (ROS) generation; these were corrected by BH4 and either L-NAME or superoxide dismutase, respectively. The protein expression of eNOS and cyclooxygenase (COX)-2 was increased in mesenteric arterioles from MSG rats. CONCLUSION Obesity/insulin resistance has a detrimental impact on vascular function. Reduced NO bioavailability and increased ROS generation from uncoupled eNOS and imbalanced release of COX products from COX-2 play a critical role in the development of these vascular alterations.
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Affiliation(s)
- N S Lobato
- Department of Pharmacology, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
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Impaired sympathoadrenal axis function contributes to enhanced insulin secretion in prediabetic obese rats. EXPERIMENTAL DIABETES RESEARCH 2011; 2011:947917. [PMID: 21860615 PMCID: PMC3157162 DOI: 10.1155/2011/947917] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/14/2011] [Accepted: 06/13/2011] [Indexed: 12/22/2022]
Abstract
The involvement of sympathoadrenal axis activity in obesity onset was investigated using the experimental model of treating neonatal rats with monosodium L-glutamate. To access general sympathetic nervous system activity, we recorded the firing rates of sympathetic superior cervical ganglion nerves in animals. Catecholamine content and secretion from isolated adrenal medulla were measured. Intravenous glucose tolerance test was performed, and isolated pancreatic islets were stimulated with glucose and adrenergic agonists. The nerve firing rate of obese rats was decreased compared to the rate for lean rats. Basal catecholamine secretion decreased whereas catecholamine secretion induced by carbachol, elevated extracellular potassium, and caffeine in the isolated adrenal medulla were all increased in obese rats compared to control. Both glucose intolerance and hyperinsulinaemia were observed in obese rats. Adrenaline strongly inhibited glucose-induced insulin secretion in obese animals. These findings suggest that low sympathoadrenal activity contributes to impaired glycaemic control in prediabetic obese rats.
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Afifi MM, Abbas AM. Monosodium glutamate versus diet induced obesity in pregnant rats and their offspring. ACTA ACUST UNITED AC 2011; 98:177-88. [PMID: 21616776 DOI: 10.1556/aphysiol.98.2011.2.9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND We aim at determining the role of monosodium glutamate (MSG) compared with high caloric chow(HCC) in development of obesity in pregnant rats and their offspring. METHODS Ninety pregnant rats were divided into 3 groups, control, MSG and HCC fed. We determined energy intake, body weight (BW), abdominal fat, fat to body weight ratio, serum glucose, insulin, leptin, lipid profile, ob and leptin receptor-b gene expressions in pregnant rats and ob and leptin receptor-b gene expressions, serum insulin,glucose, leptin, triacylglycerides (TAG), total lipids (TL) and BW in offspring. RESULTS Although daily energy intake and BW of MSG treated rats were lower than those of HCC fed rats, their abdominal fat and fat body weight ratio were higher. MSG or HCC increased Ob gene expression, leptin, insulin,LDL, cholesterol, total lipids (TL), glucose and decreased leptin receptor-b gene expression. In offspring of MSG treated rats, BW, serum glucose, insulin, leptin, TAG, TL and Ob gene expression increased and leptin receptor-b gene expression decreased whereas in offspring of HCC fed rats, serum insulin, leptin, Ob and leptin receptor-b gene expression increased but serum glucose, TAG, TL or BW did not change. CONCLUSION We conclude that in pregnant rats, MSG, in spite of mild hypophagia, caused severe increase in fat body weight ratio, via leptin resistance, whereas, HCC increased BW and fat body weight ratio, due to hyperphagia with consequent leptin resistance. Moreover, maternal obesity in pregnancy, caused by MSG, has greater impact on offspring metabolism and BW than that induced by HCC.
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Affiliation(s)
- M M Afifi
- Department of Biochemistry, Zagazig University, Zagazig, Egypt
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15
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Taurine prevents fat deposition and ameliorates plasma lipid profile in monosodium glutamate-obese rats. Amino Acids 2010; 41:901-8. [DOI: 10.1007/s00726-010-0789-7] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2010] [Accepted: 10/14/2010] [Indexed: 09/29/2022]
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16
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Abstract
Hypothalamic obesity (HyOb) was first defined as the significant polyphagia and weight gain that occurs after extensive suprasellar operations for excision of hypothalamic tumours. However, polyphagia and weight gain complicate other disorders related to the hypothalamus, including those that cause structural damage to the hypothalamus like tumours, trauma, radiotherapy; genetic disorders such as Prader-Willi syndrome; side effects of psychotropic drugs; and mutations in several genes involved in hypothalamic satiety signalling. Moreover, 'simple' obesity is associated with polymorphisms in several genes involved in hypothalamic weight-regulating pathways. Thus, understanding HyOb may enhance our understanding of 'simple' obesity. This review will claim that HyOb is a far wider phenomenon than hitherto understood by the narrow definition of post-surgical weight gain. It will emphasize the similarity in clinical characteristics and therapeutic approaches for HyOb, as well as its mechanisms. HyOb, regardless of its aetiology, is a result of impairment in hypothalamic regulatory centres of body weight and energy expenditure. The pathophysiology includes loss of sensitivity to afferent peripheral humoral signals, such as, leptin on the one hand and dysfunctional afferent signals, on the other hand. The most important afferent signals deranged are energy regulation by the sympathetic nervous system and regulation of insulin secretion. Dys-regulation of 11β-hydroxysteroid dehydrogenase 1 (11β-HSD1) activity and melatonin may also have a role in the development of HyOb. The complexity of the syndrome requires simultaneous targeting of several mechanisms that are deranged in the HyOb patient. We review the studies evaluating possible treatment strategies, including sympathomimetics, somatostatin analogues, triiodothyronine, sibutramine, and surgery.
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Affiliation(s)
- I Hochberg
- Rambam Medical Center and Rappaport Family Faculty of Medicine and Research Institute, Technion - Israel Institute of Technology, Haifa, Israel.
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17
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Cunha NV, de Abreu SB, Panis C, Grassiolli S, Guarnier FA, Cecchini R, Mazzuco TL, Pinge-Filho P, Martins-Pinge MC. Cox-2 inhibition attenuates cardiovascular and inflammatory aspects in monosodium glutamate-induced obese rats. Life Sci 2010; 87:375-81. [PMID: 20688085 DOI: 10.1016/j.lfs.2010.07.014] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2010] [Revised: 07/18/2010] [Accepted: 07/20/2010] [Indexed: 12/31/2022]
Abstract
AIMS the purpose of the present work was to investigate the effect of cyclooxygenase-2 (COX-2) inhibition on the cardiovascular and inflammatory aspects promoted by monosodium glutamate (MSG)-induced obesity in rats. MAIN METHODS Neonatal Wistar male rats were injected with MSG (4 mg/g body weight ID) or equimolar saline (control). Treatment with celecoxib (50 mg/kg ip) or saline (0.9% NaCl ip) began at 60 days of age. At 90 days, all rats were anesthetized for catheterization of the femoral artery, and the mean arterial pressure (MAP) and heart rate (HR) were recorded once consciousness was regained. KEY FINDINGS MSG obese rats were hypertensive (MAP=138±4 mm Hg) compared with controls (MAP=118±2 mm Hg). After treatment with celecoxib, the hypertension was attenuated (MAP=126±2 mm Hg) in obese rats without changes in HR. The retroperitoneal and periepididymal fat weighed more in obese rats (Obese: Retro=7.08±0.51, Peri=6.36±0.81, CONTROL: Retro=3.60±0.46; Peri=3.24±0.42), but celecoxib did not alter these parameters. Plasma nitric oxide levels were not different between groups. However, the level of plasma prostaglandins, the immunohistochemical staining of COX-2 in cardiac tissue and plasma lipoperoxidation were higher in obese rats, and celecoxib attenuated these parameters. MSG produced liver steatosis that was also attenuated following celecoxib treatment. SIGNIFICANCE Our data demonstrate an association between increased blood pressure and products of COX-2 in obese rats, suggesting a role for prostaglandins in the hypertensive and inflammatory aspects of MSG-induced obesity.
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Affiliation(s)
- N V Cunha
- Department of Physiological Sciences, State University of Londrina, Londrina, Paraná, Brazil
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18
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Trevenzoli IH, Pinheiro CR, Conceição EPS, Oliveira E, Passos MCF, Lisboa PC, Moura EG. Programming of rat adrenal medulla by neonatal hyperleptinemia: adrenal morphology, catecholamine secretion, and leptin signaling pathway. Am J Physiol Endocrinol Metab 2010; 298:E941-9. [PMID: 20304765 DOI: 10.1152/ajpendo.00734.2009] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Leptin serum concentration in early life is an important factor for adequate future development of the offspring. Previously, we demonstrated that hyperleptinemia on lactation programmed for hyperleptinemia, central leptin resistance with lower expression of the long form of leptin receptor at hypothalamus, and higher medullary catecholamine levels with cardiovascular consequences at adulthood. The central objective of this study was to determine the direct effect of leptin on adrenal medullary function of adult rats that were leptin treated during lactation. Adrenal morphology was also accessed. Recombinant murine leptin was injected in the pups during the first 10 days of life (group L, leptin-programmed) or at adulthood during 6 days (group LC). The controls of both experiments received saline (groups C and CC). Both treatments resulted in hyperleptinemia at 150 days old (+78% and 2-fold increase, respectively; P < 0.05). Programmed animals showed hypertrophy of adrenal and higher adrenal catecholamine content at 150 days old (3-fold increase, P < 0.05), and no changes were observed in the LC group. However, LC rats had lower adrenal content of tyrosine hydroxylase (-17%, P < 0.05). Leptin-programmed rats had a lower response to leptin in vitro stimulation (-22%, P < 0.05) and lower expression of key proteins of the leptin signaling pathway, leptin receptor and janus tyrosine kinase 2 in the medullas (-61% and -29%, respectively, P < 0.05). However, they presented higher expression of phosphorylated signal transducer and activator of transcription 3 (+2-fold, P < 0.05). Leptin treatment at adulthood did not affect these parameters. The higher catecholamine synthesis and secretion in the leptin-programmed rats observed in our previous study does not seem to be a consequence of the direct effect of leptin on the medullas. We suggest that the hyperleptinemia of the programmed animals increases adrenal medullary function through sympathetic nervous system activation. In conclusion, high leptin levels on lactation program the activity of the sympathoadrenal system at adulthood that may contribute to the development of adult chronic diseases such as hypertension.
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Affiliation(s)
- I H Trevenzoli
- Departamento de Ciências Fisiológicas, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, 20551-030, Brazil
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Scomparin DX, Gomes RM, Grassiolli S, Rinaldi W, Martins AG, de Oliveira JC, Gravena C, de Freitas Mathias PC. Autonomic activity and glycemic homeostasis are maintained by precocious and low intensity training exercises in MSG-programmed obese mice. Endocrine 2009; 36:510-7. [PMID: 19856134 DOI: 10.1007/s12020-009-9263-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2009] [Accepted: 09/18/2009] [Indexed: 12/13/2022]
Abstract
Current research employed electrical records from superior vagus and sympathetic nerve branch that supply fat retroperitoneal tissue (RS nerve) to investigate whether very moderate swim training in obese-programmed mice would change sympathetic and parasympathetic autonomic nervous system activities. Neonatal mice were treated with monosodium L: -glutamate (MSG), during their first 5 days of life, to induce obesity. Mice started training on weaning, comprising free swimming 3 days/week, 15 min/day for 10 weeks. After 12 h fasting, the nerve electrical signals of the 90-day-old mice were processed to obtain firing rates. Blood samples were collected to measure glucose and insulin levels. Adrenal catecholamine content was measured. MSG treatment caused obesity. Hyperglycemia and hyperinsulinemia in MSG-obese mice, without any change in food intake, were obtained. Vagus firing rates were higher in obese mice than those in lean ones. A decrease in RS nerve activity and lower adrenal catecholamine stores have been observed. Swimming normalized blood glucose and insulin levels and MSG-obesity onset was attenuated by exercise. Vagus activity from obese mice decreased, whereas RS nerve activity and adrenal catecholamine levels increased in trained ones. Results suggest that autonomic activity imbalance and metabolic dysfunctions observed in MSG-obese mice were inhibited by precocious and moderate exercise training.
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Affiliation(s)
- Dionizia Xavier Scomparin
- Laboratory of Secretion Cell Biology, Department of Cell Biology and Genetics, State University of Maringá, Avenida Colombo 5790, Bloco H-67, S/019, Maringá, PR 87020-900, Brazil
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20
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Abstract
Hypothalamic injury from acquired structural damage due to infiltrative disease, tumor, or their treatment aftereffects frequently results in the development of an obesity syndrome characterized by a rapid, unrelenting weight gain that may be accompanied by severe hyperphagia. Weight gain occurs from the disruption of the normal homeostatic functioning of the hypothalamic centers responsible for controlling satiety and hunger and regulating energy balance with resulting hyperphagia, autonomic imbalance, reduction of energy expenditure, and hyperinsulinemia. Curtailment of weight increase has traditionally been refractory to usual dietary and lifestyle interventions. Pharmacotherapy targeting insulin secretion and augmenting sympathetic output have been attempted to promote weight loss or attenuate weight gain. In addition, case reports suggest that bariatric surgery may be an effective treatment option for these patients. Hormonal deficits are often present, and their management may also have consequences for weight control. Hypothalamic obesity confers significant morbidity and mortality, and there is a need for greater elucidation of its risk factors and pathogenesis so that more effective interventions can be developed.
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Affiliation(s)
- Michelle Lee
- Department of Medicine, Columbia University College of Physicians & Surgeons, 630 West 168th Street, New York, NY, 10032, USA.
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21
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Tilbrook AJ, Rivalland EAT, Turner AI, Lambert GW, Clarke IJ. Responses of the hypothalamopituitary adrenal axis and the sympathoadrenal system to isolation/restraint stress in sheep of different adiposity. Neuroendocrinology 2008; 87:193-205. [PMID: 18285679 DOI: 10.1159/000117576] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2007] [Accepted: 11/11/2007] [Indexed: 11/19/2022]
Abstract
There is evidence that levels of adipose tissue can influence responses of the hypothalamopituitary-adrenal (HPA) axis to stress in humans and rats but this has not been explored in sheep. Also, little is known about the sympathoadrenal responses to stress in individuals with relatively different levels of adipose tissue. We tested the hypothesis that the stress-induced activation of the HPA axis and sympathoadrenal system is lower in ovariectomized ewes with low levels of body fat (lean) than ovariectomized ewes with high levels of body fat (fat). Ewes underwent dietary manipulation for 3 months to yield a group of lean ewes (n = 7) with a mean (+/-SEM) live weight of 39.1 +/- 0.9 kg and body fat of 8.9 +/- 0.6% and fat ewes (n = 7) with a mean (+/-SEM) live weight of 69.0 +/- 1.8 kg and body fat of 31.7 +/- 3.4%. Fat ewes also had higher circulating concentrations of leptin than lean ewes. Blood samples were collected every 15 min over 8 h when no stress was imposed (control day) and on a separate day when 4 h of isolation/restraint was imposed after 4 h of pretreatment sampling (stress day). Plasma concentrations of adrenocorticotropic hormone (ACTH), cortisol, epinephrine and norepinephrine did not change significantly over the control day and did not differ between lean and fat ewes. Stress did not affect plasma leptin levels. All stress hormones increased significantly during isolation/restraint stress. The ACTH, cortisol and epinephrine responses were greater in fat ewes than lean ewes but norepinephrine responses were similar. Our results suggest that relative levels of adipose tissue influence the stress-induced activity of the hypothalamopituitary-adrenal axis and some aspects of the sympathoadrenal system with fat animals having higher responses than lean animals.
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Affiliation(s)
- Alan J Tilbrook
- Department of Physiology, Monash University, Monash, Vic., Australia.
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22
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Fagundes ATS, Moura EG, Passos MCF, Oliveira E, Toste FP, Bonomo IT, Trevenzoli IH, Garcia RMG, Lisboa PC. Maternal low-protein diet during lactation programmes body composition and glucose homeostasis in the adult rat offspring. Br J Nutr 2007; 98:922-8. [PMID: 17524178 DOI: 10.1017/s0007114507750924] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Previously we have reported that maternal malnutrition during lactation programmes body weight and thyroid function in the adult offspring. In the present study we evaluated the effect of maternal protein restriction during lactation upon body composition and hormones related to glucose homeostasis in adult rats. During lactation, Wistar lactating rats and their pups were divided into two experimental groups: control (fed a normal diet; 23 % protein) and protein-restricted (PR; fed a diet containing 8 % protein). At weaning, offspring received a normal diet until they were 180 d old. Body weight (BW) and food intake were monitored. Serum, adrenal glands, visceral fat mass (VFM) and carcasses were collected. PR rats showed lower BW ( − 13 %;P < 0·05), VFM ( − 33 %;P < 0·05), total body fat ( − 33 %;P < 0·05), serum glucose ( − 7 %;P < 0·05), serum insulin ( − 26 %,P < 0·05), homeostasis model assessment index ( − 20 %), but higher total adrenal catecholamine content (+90 %;P < 0·05) and serum corticosterone concentration (+51 %;P < 0·05). No change was observed in food intake, protein mass or total body water. The lower BW of PR rats is due to a reduction of white fat tissue, probably caused by an increase in lipolysis or impairment of lipogenesis; both effects could be related to higher catecholaminergic status, as well as to hypoinsulinaemia. To conclude, changes in key hormones which control intermediary metabolism are programmed by maternal protein restriction during lactation, resulting in BW alterations in adult rats.
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Affiliation(s)
- A T S Fagundes
- Departamento de Ciências Fisiológicas, Instituto de Biologia Roberto Alcântara Gomes, Universidade do Estado do Rio de Janeiro, Av. 28 de Setembro, 87, Rio de Janeiro, RJ, 20551-030, Brasil
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Von Diemen V, Trindade EN, Trindade MRM. [Experimental model to induce obesity in rats]. Acta Cir Bras 2007; 21:425-9. [PMID: 17160257 DOI: 10.1590/s0102-86502006000600013] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2006] [Accepted: 09/18/2006] [Indexed: 01/25/2023] Open
Abstract
The etiology of obesity is multifactorial and is becoming a problem of public health, due to its increased prevalence and the consequent repercussion of its comorbidities on the health of the population. The great similarity and homology between the genomes of rodents and humans make these animal models a major tool to study conditions affecting humans, which can be simulated in rats. Obesity can be induced in animals by neuroendocrine, dietary or genetic changes. The most widely used models to induce obesity in rats are a lesion of the ventromedial hypothalamic nucleus (VMH) by administering monosodium glutamate or a direct electrical lesion, ovariectomy, feeding on hypercaloric diets and genetic manipulation for obesity.
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Trevenzoli IH, Valle MMR, Machado FB, Garcia RMG, Passos MCF, Lisboa PC, Moura EG. Neonatal hyperleptinaemia programmes adrenal medullary function in adult rats: effects on cardiovascular parameters. J Physiol 2007; 580:629-37. [PMID: 17218354 PMCID: PMC2075542 DOI: 10.1113/jphysiol.2006.126151] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Epidemiological studies have shown a strong correlation between stressful events (nutritional, hormonal or environmental) in early life and development of adult diseases such as obesity, diabetes and cardiovascular failure. It is known that gestation and lactation are crucial periods for healthy growth in mammals and that the sympathoadrenal system is markedly influenced by environmental conditions during these periods. We previously demonstrated that neonatal hyperleptinaemia in rats programmes higher body weight, higher food intake and hypothalamic leptin resistance in adulthood. Using this model of programming, we investigated adrenal medullary function and effects on cardiovascular parameters in male rats in adulthood. Leptin treatment during the first 10 days of lactation (8 microg 100 g(-1) day(-1), s.c.) resulted in lower body weight (6.5%, P < 0.05), hyperleptinaemia (10-fold, P < 0.05) and higher catecholamine content in adrenal glands (18.5%, P < 0.05) on the last day of treatment. In adulthood (150 days), the rats presented higher body weight (5%, P < 0.05), adrenal catecholamine content (3-fold, P < 0.05), tyrosine hydroxylase expression (35%, P < 0.05) and basal and caffeine-stimulated catecholamine release (53% and 100%, respectively, P < 0.05). Systolic blood pressure and heart rate were also higher in adult rats (7% and 6%, respectively, P < 0.05). Our results show that hyperleptinaemia in early life increases adrenal medullary function in adulthood and that this may alter cardiovascular parameters. Thus, we suggest that imprinting factors which increase leptin and catecholamine levels during the neonatal period could be involved in development of adult chronic diseases.
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Affiliation(s)
- I H Trevenzoli
- Physiology Department, Alcântara Gomes Biology Institute, State University of Rio de Janeiro, RJ, 20551-030, Brazil
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Scomparin DX, Grassiolli S, Marçal AC, Gravena C, Andreazzi AE, Mathias PCF. Swim training applied at early age is critical to adrenal medulla catecholamine content and to attenuate monosodium l-glutamate-obesity onset in mice. Life Sci 2006; 79:2151-6. [PMID: 16934841 DOI: 10.1016/j.lfs.2006.07.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2006] [Revised: 06/30/2006] [Accepted: 07/11/2006] [Indexed: 10/24/2022]
Abstract
Exercise has been recommended as a remedy against a worldwide obesity epidemic; however, the onset of excessive weight gain is not fully understood, nor are the effects of exercise on body weight control. Activity deficits of the sympathetic nervous system, including the sympathoadrenal axis, have been suggested to contribute to high fat accumulation in obesity. In the present work, swim training was used to observe fat accumulation and adrenal catecholamine stocks in hypothalamic-obese mice produced by neonatal treatment with monosodium L-glutamate (MSG). MSG-treated and normal mice swam for 15 min/day, 3 days a week, from weaning up to 90 days old (EXE 21-90); from weaning up to 50 days old (EXE 21-50) and from 60 up to 90 days old (EXE 60-90). Sedentary MSG and normal mice (SED groups) did not exercise at all. Animals were sacrificed at 90 days of age. MSG treatment induced obesity, demonstrated by a 43.08% increase in epididymal fat pad weight; these adult obese mice presented 27.7% less catecholamine stocks in their adrenal glands than untreated mice (p<0.001). Exercise reduced fat accumulation and increased adrenal catecholamine content in EXE 21-90 groups. These effects were more pronounced in MSG-mice than in normal ones. Halting the exercise (EXE 21-50 groups) still changed fat accretion and catecholamine stocks; however, no effects were recorded in the EXE 60-90 groups. We conclude that metabolic changes imposed by early exercise, leading to an attenuation of MSG-hypothalamic obesity onset, are at least in part due to sympathoadrenal activity modulation.
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Affiliation(s)
- D X Scomparin
- Laboratory of Secretion Cell Biology, Department of Cell Biology and Genetics, State University of Maringá, Av. Colombo 5790, Bloco H-67, S/019, 87020-900 Maringá PR Brazil
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Kim YW, Choi DW, Park YH, Huh JY, Won KC, Choi KH, Park SY, Kim JY, Lee SK. Leptin-like effects of MTII are augmented in MSG-obese rats. ACTA ACUST UNITED AC 2005; 127:63-70. [PMID: 15680471 DOI: 10.1016/j.regpep.2004.10.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2004] [Accepted: 10/21/2004] [Indexed: 11/16/2022]
Abstract
To evaluate whether MTII, a melanocortin receptor 3/4 agonist, is working in hypophagic and hypothermogenic obese model, we measured food intake, body weight, oxygen consumption, and fat mass following intracerebroventricular (i.c.v.) infusion of MTII in monosodium glutamate (MSG)-induced obese rats. MTII, or artificial cerebrospinal fluid (aCSF), was infused into i.c.v. with an osmotic minipump for 1 week. MSG-obese rats were induced by neonatal injection of MSG. Five-month-old MSG rats were characterized by hypophagia, lower oxygen consumption, hyperleptinemia, and obesity compared to age-matched control rats. The infusion of MTII decreased their food intake, visceral fat, and body weight in MSG-obese rats compared with aCSF-infused rats. The oxygen consumption was increased by MTII treatment in MSG-obese rats compared with aCSF as well as pair fed (PF) rats. Interestingly, these leptin-like effects of MTII were greater in MSG-obese rats than in controls, which might be related to the increased expression of melanocortin receptor 4 (MC4R) in the hypothalamus of MSG-obese rats. Our results suggested that both anorexic and thermogenic mechanisms were activated by MTII in the MSG-obese rats and contributed to the decrease in body weight and fat mass. Moreover, there was a sensitization to MTII caused by upregulation of the melanocortin receptor in the MSG-obese rats.
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Affiliation(s)
- Yong-Woon Kim
- Department of Physiology, College of Medicine, Yeungnam University, #317-1, Daemyungdong, Namgu, Daegu 705-717, Republic of Korea.
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