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Cunha TRD, Giesen JAS, Rouver WN, Costa ED, Grando MD, Lemos VS, Bendhack LM, Santos RLD. Effects of progesterone treatment on endothelium-dependent coronary relaxation in ovariectomized rats. Life Sci 2020; 247:117391. [PMID: 32017871 DOI: 10.1016/j.lfs.2020.117391] [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: 09/06/2019] [Revised: 01/22/2020] [Accepted: 01/30/2020] [Indexed: 12/24/2022]
Abstract
AIM Although progesterone (P4) has a beneficial effect on the cardiovascular system, P4 actions on the coronary bed have not yet been fully elucidated. This study evaluated the effect of progesterone treatment on endothelium-dependent coronary vascular reactivity in Wistar rats. MAIN METHODS Eight-week-old adult rats were divided into Sham, Ovariectomized (OVX), Ovariectomized and progesterone treated (OVX P4). The OVX P4 group received daily doses of progesterone (2 mg/kg/day). Vascular reactivity was assessed by a modified Langendorff technique. The intensity of eNOS, Akt, and gp91phox protein expression was quantified by Western blotting. Superoxide anion (O2●-) and hydrogen peroxide (H2O2) production was measured by dihydroethidium and 2',7'-dichlorofluorescein, respectively. KEY FINDINGS Treatment with P4 was able to prevent the reduction in baseline coronary perfusion pressure induced by ovariectomy. We observed that endothelium-dependent coronary vasodilation was reduced in the OVX group and potentiated in the OVX P4 group. Following the inhibition of the nitric oxide (NO) pathway, the bradykinin-induced relaxing response was potentiated in the OVX P4 group. With regard to the combined inhibition of NO and prostanoids pathways, the OVX P4 group showed a greater relaxing response, similar to what was found upon individual inhibition of NO. After the combined inhibition of NO, prostanoids and epoxyeicosatrienoic acids' pathways, the vasodilatory response induced by BK was abolished in all groups. SIGNIFICANCE Treatment with P4 prevented oxidative stress induced by ovariectomy. These results suggest that progesterone has a beneficial action on the coronary vascular bed.
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Affiliation(s)
- Tagana Rosa da Cunha
- Department of Physiological Sciences, Health Sciences Center, Federal University of Espirito Santo, Vitoria, ES, Brazil
| | | | - Wender Nascimento Rouver
- Department of Physiological Sciences, Health Sciences Center, Federal University of Espirito Santo, Vitoria, ES, Brazil
| | - Eduardo Damasceno Costa
- Department of Physiology and Biophysics, Biological Sciences Institute, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Marcella Daruge Grando
- Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Virgínia Soares Lemos
- Department of Physiology and Biophysics, Biological Sciences Institute, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Lusiane Maria Bendhack
- Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Roger Lyrio Dos Santos
- Department of Physiological Sciences, Health Sciences Center, Federal University of Espirito Santo, Vitoria, ES, Brazil.
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Romão CM, Pereira RC, Shimizu MHM, Furukawa LNS. N-acetyl-l-cysteine exacerbates kidney dysfunction caused by a chronic high-sodium diet in renal ischemia and reperfusion rats. Life Sci 2019; 231:116544. [PMID: 31181229 DOI: 10.1016/j.lfs.2019.116544] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 06/03/2019] [Accepted: 06/05/2019] [Indexed: 01/01/2023]
Abstract
AIMS To investigate the effect of long-term N-acetyl-l-cysteine (NAC) treatment in Wistar rats subjected to renal ischemia and reperfusion (IR) and a chronic high‑sodium diet (HSD). MAIN METHODS Adult male Wistar rats received an HSD (8.0% NaCl) or a normal‑sodium diet (NSD; 1.3% NaCl) and NAC (600 mg/L) or normal drinking water starting at 8 weeks of age. At 11 weeks of age, the rats from both diet and NAC or water treatment groups underwent renal IR or Sham surgery and were followed for 10 weeks. The study consisted of six animal groups: NSD + Sham + water; NSD + IR + water; NSD + IR + NAC; HSD + Sham + water; HSD + IR + water; and HSD + IR + NAC. KEY FINDINGS Tail blood pressure (tBP) increased with IR and NAC treatment in the NSD group but not in the HSD group. The serum creatinine level was higher after NAC treatment in both diet groups, and creatinine clearance was decreased in only the HSD + IR + NAC group. Albuminuria increased in the HSD + IR + water group and decreased in the HSD + IR + NAC group. Kidney mass was increased in the HSD + IR group and decreased with NAC treatment. Renal fibrosis was prevented with NAC treatment and cardiac fibrosis was decreased with NAC treatment in the HSD + IR group. SIGNIFICANCE NAC treatment promoted structural improvements, such as decreased albuminuria and fibrosis, in the kidney and heart. However, NAC could not recover kidney function or blood pressure from the effects of IR associated with an HSD. Therefore, in general, long-term NAC treatment is not effective and is deleterious to recovery of function after kidney injury.
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Affiliation(s)
- Carolina Martinez Romão
- Laboratory of Renal Pathophysiology, Department of Internal Medicine, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Rafael Canavel Pereira
- Laboratory of Renal Pathophysiology, Department of Internal Medicine, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Maria Heloisa Massola Shimizu
- Laboratory of Renal Pathophysiology, Department of Internal Medicine, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Luzia Naôko Shinohara Furukawa
- Laboratory of Renal Pathophysiology, Department of Internal Medicine, School of Medicine, University of São Paulo, São Paulo, Brazil.
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3
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He L, Liu YJ, Zheng T, Tan ZJ. Effect of high-salt diet on health: Relationship with intestinal microflora. Shijie Huaren Xiaohua Zazhi 2018; 26:143-149. [DOI: 10.11569/wcjd.v26.i3.143] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Salt is the most basic and commonly used seasoning agent in daily diet. It is an important part of all kinds of food and plays a vital role in food preparation and preservation. People are increasingly in pursuit of a healthy diet to reduce the incidence of dietary-related diseases and to improve their health. Salt intake and related diseases have become the focus of research, and salt intake is considered the main factor for a healthy diet. This paper reviews the progress in research of the effect of high-salt diet on health with regard to intestinal microbiota, metabolic pathogenicity, and epidemiological investigation, and other aspects of salt consumption. Cardiovascular, endocrine, and other chronic diseases have been associated with high salt diet. A better understanding of the effect of high salt intake on health can improve the prevention and treatment of chronic diseases and provide new ideas for the development of scientific diet programs.
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Affiliation(s)
- Lu He
- Department of Microbiology, Hunan University of Chinese Medicine, Changsha 410208, Hunan Province, China
| | - You-Jia Liu
- Department of Microbiology, Hunan University of Chinese Medicine, Changsha 410208, Hunan Province, China
| | - Tao Zheng
- Department of Microbiology, Hunan University of Chinese Medicine, Changsha 410208, Hunan Province, China
| | - Zhou-Jin Tan
- Department of Microbiology, Hunan University of Chinese Medicine, Changsha 410208, Hunan Province, China
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Homma T, Homma M, Huang Y, Mayurasakorn K, Rodi NM, Hamid AAA, Hurwitz S, Yao T, Adler GK, Pojoga LH, Williams GH, Romero JR. Combined Salt and Caloric Restrictions: Potential Adverse Outcomes. J Am Heart Assoc 2017; 6:e005374. [PMID: 29021272 PMCID: PMC5721821 DOI: 10.1161/jaha.116.005374] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 07/25/2017] [Indexed: 11/23/2022]
Abstract
BACKGROUND We hypothesized that caloric restriction (CR) and salt restriction (ResS) would have similar effects on reducing cardiovascular risk markers and that combining CR and ResS would be synergistic in modulating these markers. METHODS AND RESULTS To test our hypothesis, rats were randomized into 2 groups: ad libitum liberal salt diet (ad libitum/high-sodium, 1.6% sodium) or ResS diet (ad libitum/ResS, 0.03% sodium). CR was initiated in half of the rats in each group by reducing caloric intake to 60% while maintaining sodium intake constant (CR/high-sodium, 2.7% sodium or CR/ResS, 0.05% sodium) for 4 weeks. CR in rats on a high-sodium diet improved metabolic parameters, renal transforming growth factor-β and collagen-1α1 and increased plasma adiponectin and renal visfatin and NAD+ protein levels. Although CR produced some beneficial cardiovascular effects (increased sodium excretion and reduced blood pressure), it also was associated with potentially adverse cardiovascular effects. Adrenal zona glomerulosa cell responsiveness and aldosterone levels and activation were inappropriately increased for the volume state of the rodent. Like CR on HS, CR on a ResS diet also produced relative increased zona glomerulosa responsiveness and an increased blood pressure with no improvement in metabolic parameters. CONCLUSIONS These results suggest that combining CR and ResS may decrease the beneficial effects of each alone. Furthermore, CR, regardless of dietary salt intake, inappropriately activates aldosterone production. Thus, caution should be used in combining ResS and CR because the combination may lead to increased cardiovascular risk.
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Affiliation(s)
- Tsuyoshi Homma
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, Boston, MA
| | - Mika Homma
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, Boston, MA
| | - Yuefei Huang
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, Boston, MA
| | - Korapat Mayurasakorn
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, Boston, MA
| | - Nurul Mahamad Rodi
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, Boston, MA
| | | | - Shelley Hurwitz
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, Boston, MA
| | - Tham Yao
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, Boston, MA
| | - Gail K Adler
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, Boston, MA
| | - Luminita H Pojoga
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, Boston, MA
| | - Gordon H Williams
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, Boston, MA
| | - Jose R Romero
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, Boston, MA
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High maternal sodium intake alters sex-specific renal renin-angiotensin system components in newborn Wistar offspring. J Dev Orig Health Dis 2016; 7:282-289. [PMID: 26818798 DOI: 10.1017/s2040174416000015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
This study aimed to evaluate the systemic and renal renin-angiotensin-aldosterone system (RAAS) at birth in male and female offspring and in mothers fed a high sodium diet (HSD) before and during gestation. Female Wistar rats were fed a HSD (8.0% NaCl) or a normal sodium diet (1.3% NaCl) from 8 weeks of age until delivery of their first litter. Maternal body weight, tail blood pressure, and food and water intake were evaluated. The litter sizes were assessed, and the body and kidney weights of the offspring were measured. Both mothers and offspring were euthanized immediately following the birth of the pups to evaluate plasma renin activity (PRA), renal renin content (RRC), renal angiotensin-converting enzyme (ACE) activity, renal angiotensin (Ang) II content, serum aldosterone (ALDO) levels, and renal cortical and medullary renin messenger RNA expression. In mothers in the HSD group, water intake and kidney mass were higher, whereas renal ACE activity, Ang II, PRA, ALDO and RRC were decreased. In the offspring of HSD-fed dams, the body and kidney mass were lower in both genders, renal ACE activity was lower in females and renal Ang II was lower in males. PRA, RRC, renin gene expression and ALDO levels did not differ between the groups of offspring. The data presented herein showed that a maternal HSD during pregnancy induces low birth weight and a sex-specific response in the RAAS in offspring.
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Low-salt diet increases NO bioavailability and COX-2 vasoconstrictor prostanoid production in spontaneously hypertensive rats. Life Sci 2015; 145:66-73. [PMID: 26685759 DOI: 10.1016/j.lfs.2015.12.027] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 11/12/2015] [Accepted: 12/09/2015] [Indexed: 12/17/2022]
Abstract
AIMS The ability of dietary sodium restriction to reduce the incidence of cardiovascular mortality and improve vascular function in hypertension still remains poorly understood. The aim of this study was to observe the effects of a long period of salt restriction on the vascular reactivity of mesenteric resistance arteries of SHRs. METHODS Male SHRs received either standard-salt diet (0.3% NaCl) or low-salt diet (0.03% NaCl) for 28weeks. Vascular reactivity was studied in mesenteric artery segments and the influence of cyclooxygenase-2 (COX-2), reactive oxygen species (ROS) and participation of the renin-angiotensin system were analyzed. KEY FINDINGS Decreased salt intake did not affect phenylephrine-induced vasoconstriction but increased acetylcholine-induced vasodilatation and also increased the response to phenylephrine after inhibition of NO synthase by L-NAME (100μM) and iNOS protein expression was elevated. Cyclooxygenase inhibitor indomethacin (10μM) and COX-2 inhibitor NS 398 (1μM) decreased the reactivity to phenylephrine in low-salt-treated group, and COX-2 protein expression was elevated in low-salt group. The effects of apocynin (10μM); superoxide anion scavenger, tiron (1mM); hydrogen peroxide scavenger, catalase (1000UmL(-1)); and ACE and AT1 receptor blockers, enalapril (10μM) and losartan (10μM) on vascular reactivity were not different between two groups. The levels of AT1 protein expression were similar in both groups. SIGNIFICANCE Low-salt diet modulates mesenteric vascular responses via increased NO bioavailability suggested by increased iNOS protein expression and vasoconstrictor prostanoid production via COX-2 pathway, in SHRs. Neither ROS nor the local renin-angiotensin system is involved in these responses.
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Effects of high and low salt intake on left ventricular remodeling after myocardial infarction in normotensive rats. ACTA ACUST UNITED AC 2015; 9:77-85. [DOI: 10.1016/j.jash.2014.11.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2014] [Revised: 11/26/2014] [Accepted: 11/30/2014] [Indexed: 12/16/2022]
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Zhang Y, Liou WW, Gupta V. Modeling of high sodium intake effects on left ventricular hypertrophy. Comput Biol Med 2015; 58:31-9. [PMID: 25601615 DOI: 10.1016/j.compbiomed.2014.12.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Revised: 12/06/2014] [Accepted: 12/18/2014] [Indexed: 01/19/2023]
Abstract
Many clinical studies suggest that chronic high sodium intake contributes to the development of essential hypertension and left ventricular (LV) hypertrophy. In the present study, a system-level computer model has been developed to simulate the long-term effects of increased sodium intake on the LV mechanical functions and the body-fluid homeostasis. The new model couples a cardiovascular hemodynamics function model with an explicit account of the LV wall thickness variation and a long-term renal system model. The present model is validated with published results of clinical studies. The results suggest that, with increased sodium intake, the renal system function, the plasma hormone concentrations, and the blood pressure adapt to new levels of equilibrium. The LV work output and the relative wall thickness increase due to the increase of sodium intake. The results of the present model match well with the patient data.
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Affiliation(s)
- Yan Zhang
- Department of Mechanical and Aerospace Engineering, Western Michigan University, Kalamazoo, Michigan, USA
| | - William W Liou
- Department of Mechanical and Aerospace Engineering, Western Michigan University, Kalamazoo, Michigan, USA.
| | - Vishal Gupta
- Borgess Medical Center, Borgess Research Institute, Kalamazoo, Michigan, USA
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9
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Ferreira DN, Katayama IA, Oliveira IB, Rosa KT, Furukawa LNS, Coelho MS, Casarini DE, Heimann JC. Salt-induced cardiac hypertrophy and interstitial fibrosis are due to a blood pressure-independent mechanism in Wistar rats. J Nutr 2010; 140:1742-51. [PMID: 20724490 DOI: 10.3945/jn.109.117473] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
High salt intake is a known cardiovascular risk factor and is associated with cardiac alterations. To better understand this effect, male Wistar rats were fed a normal (NSD: 1.3% NaCl), high 4 (HSD4: 4%), or high 8 (HSD8: 8%) salt diet from weaning until 18 wk of age. The HSD8 group was subdivided into HSD8, HSD8+HZ (15 mg . kg(-1) . d(-1) hydralazine in the drinking water), and HSD8+LOS (20 mg . kg(-1) . d(-1) losartan in the drinking water) groups. The cardiomyocyte diameter was greater in the HSD4 and HSD8 groups than in the HSD8+LOS and NSD groups. Interstitial fibrosis was greater in the HSD4 and HSD8 groups than in the HSD8+HZ and NSD groups. Hydralazine prevented high blood pressure (BP) and fibrosis, but not cardiomyocyte hypertrophy. Losartan prevented high BP and cardiomyocyte hypertrophy, but not fibrosis. Angiotensin II type 1 receptor (AT(1)) protein expression in both ventricles was greater in the HSD8 group than in the NSD group. Losartan, but not hydralazine, prevented this effect. Compared with the NSD group, the binding of an AT(1) conformation-specific antibody that recognizes the activated form of the receptor was lower in both ventricles in all other groups. Losartan further lowered the binding of the anti-AT(1) antibody in both ventricles compared with all other experimental groups. Angiotensin II was greater in both ventricles in all groups compared with the NSD group. Myocardial structural alterations in response to HSD are independent of the effect on BP. Salt-induced cardiomyocyte hypertrophy and interstitial fibrosis possibly are due to different mechanisms. Evidence from the present study suggests that salt-induced AT(1) receptor internalization is probably due to angiotensin II binding.
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Affiliation(s)
- Daniele N Ferreira
- Laboratory of Experimental Hypertension, University of São Paulo, São Paulo 01246-903, Brazil
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10
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Uncoupling protein 2 ablation exacerbates high-salt intake-induced vascular dysfunction. Am J Hypertens 2010; 23:822-8. [PMID: 20395942 DOI: 10.1038/ajh.2010.73] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND Salt-induced vascular dysfunction in which underlying mechanisms involve reactive oxygen species (ROS)-mediated reduction of nitric oxide (NO) bioavailability has been well documented. Uncoupling protein 2 (UCP2) has been implicated in the vascular protection, specifically by decreasing ROS production. However, it is unclear how UCP2 affects vascular function in salt-loaded mice. METHODS UCP2-deficient (UCP2(-/-)) and wild-type (WT) mice were placed on either a normal-salt (NS, 0.5%) or a high-salt (HS, 8%) diet for 24 weeks. Blood pressure (BP), mesenteric arterial reactivity, superoxide production, and NO bioavailability in the intact vessels were measured in each group. RESULTS UCP2(-/-) mice on a HS diet had a higher BP than those on a NS diet (P < 0.01). However, BP in WT mice was not different between the NS and HS diet group. Phenylephrine (PE)-induced contraction was enhanced while acetylcholine (ACh)-elicited relaxation was impaired in mesenteric resistance arteries from the HS diet-fed WT mice. Importantly, the enhanced contraction and impaired relaxation were both further exacerbated in UCP2(-/-) mice. Similarly, the HS diet led to a moderate increase in superoxide production and a comparable decrease in NO availability in both aortas and mesenteric resistance vessels, and these effects were also remarkably enhanced in UCP2(-/-) mice. CONCLUSIONS These findings suggest that UCP2 plays an important role in preventing salt-sensitive hypertension, which may be achieved by suppressing superoxide production and reserving NO bioavailability in blood vessels.
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Lima N, Tozetto D, Lima L, Nobre F, Moriguti J, Ferriolli E, Foss M. Salt and insulin sensitivity after short and prolonged high salt intake in elderly subjects. Braz J Med Biol Res 2009; 42:738-43. [DOI: 10.1590/s0100-879x2009000800008] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2008] [Accepted: 05/13/2009] [Indexed: 02/05/2023] Open
Affiliation(s)
| | | | | | - F. Nobre
- Universidade de São Paulo, Brasil
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12
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Fonseca-Alaniz MH, Takada J, Andreotti S, de Campos TBF, Campaña AB, Borges-Silva CN, Lima FB. High sodium intake enhances insulin-stimulated glucose uptake in rat epididymal adipose tissue. Obesity (Silver Spring) 2008; 16:1186-92. [PMID: 18369340 DOI: 10.1038/oby.2008.69] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE This study investigated the effect of different sodium content diets on rat adipose tissue carbohydrate metabolism and insulin sensitivity. METHODS AND PROCEDURES Male Wistar rats were fed on normal- (0.5% Na(+); NS), high- (3.12% Na(+); HS),or low-sodium (0.06% Na(+); LS) diets for 3, 6, and 9 weeks after weaning. Blood pressure (BP) was measured using a computerized tail-cuff system. An intravenous insulin tolerance test (ivITT) was performed in fasted animals. At the end of each period, rats were killed and blood samples were collected for glucose and insulin determinations. The white adipose tissue (WAT) from abdominal and inguinal subcutaneous (SC) and periepididymal (PE) depots were weighed and processed for adipocyte isolation and measurement of in vitro rates of insulin-stimulated 2-deoxy-D-[(3)H]-glucose uptake (2DGU) and conversion of -[U-(14)C]-glucose into (14)CO(2). RESULTS After 6 weeks, HS diet significantly increased the BP, SC and PE WAT masses, PE adipocyte size, and plasma insulin concentration. The sodium dietary content did not influence the whole-body insulin sensitivity. A higher half-maximal effective insulin concentration (EC(50)) from the dose-response curve of 2DGU and an increase in the insulin-stimulated glucose oxidation rate were observed in the isolated PE adipocytes from HS rats. DISCUSSION The chronic salt overload enhanced the adipocyte insulin sensitivity for glucose uptake and the insulin-induced glucose metabolization, contributing to promote adipocyte hypertrophy and increase the mass of several adipose depots, particularly the PE fat pad.
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MESH Headings
- Adipocytes, White/drug effects
- Adipocytes, White/metabolism
- Adipocytes, White/pathology
- Adipose Tissue/pathology
- Adipose Tissue, White/drug effects
- Adipose Tissue, White/metabolism
- Adipose Tissue, White/pathology
- Animals
- Biological Transport/drug effects
- Blood Glucose/metabolism
- Blood Pressure/drug effects
- Body Weight/physiology
- Cells, Cultured
- Dose-Response Relationship, Drug
- Epididymis/drug effects
- Epididymis/metabolism
- Epididymis/pathology
- Glucose/metabolism
- Glucose/pharmacokinetics
- Heart Rate/drug effects
- Hypertrophy
- Insulin/blood
- Insulin/pharmacology
- Male
- Rats
- Rats, Wistar
- Sodium, Dietary/pharmacology
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Affiliation(s)
- Miriam H Fonseca-Alaniz
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
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Fonseca-Alaniz MH, Brito LC, Borges-Silva CN, Takada J, Andreotti S, Lima FB. High dietary sodium intake increases white adipose tissue mass and plasma leptin in rats. Obesity (Silver Spring) 2007; 15:2200-8. [PMID: 17890487 DOI: 10.1038/oby.2007.261] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Salt restriction has been reported to increase white adipose tissue (WAT) mass in rodents. The objective of this study was to investigate the effect of different sodium content diets on the lipogenic and lipolytic activities of WAT. RESEARCH METHODS AND PROCEDURES Male Wistar rats were fed on normal-sodium (NS; 0.5% Na(+)), high-sodium (HS; 3.12% Na(+)), or low-sodium (LS; 0.06% Na(+)) diets for 3, 6, and 9 weeks after weaning. Blood pressure (BP) was measured using a computerized tail-cuff system. At the end of each period, rats were killed and blood samples were collected for leptin determinations. The WAT from abdominal and inguinal subcutaneous (SC), periepididymal (PE) and retroperitoneal (RP) depots was weighed and processed for adipocyte isolation, rate measurement of lipolysis and d-[U-(14)C]-glucose incorporation into lipids, glucose-6-phosphate dehydrogenase (G6PDH) and malic enzyme activity evaluation, and determination of G6PDH and leptin mRNA expression. RESULTS After 6 weeks, HS diet significantly increased BP; SC, PE, and RP WAT masses; PE adipocyte size; plasma leptin concentration; G6PDH activity in SC WAT; and PE depots and malic activity only in SC WAT. The leptin levels correlated positively with WAT masses and adipocyte size. An increase in the basal and isoproterenol-stimulated lipolysis and in the ability to incorporate glucose into lipids was observed in isolated adipocytes from HS rats. DISCUSSION HS diet induced higher adiposity characterized by high plasma leptin concentration and adipocyte hypertrophy, probably due to an increased lipogenic capacity of WAT.
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Affiliation(s)
- Miriam H Fonseca-Alaniz
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, 1524 Prof Lineu Prestes Ave., 05508-900, Sao Paulo, SP, Brazil
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