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Wang H, Tian Y, Chen Y, Shen X, Pan L, Li G. Hyperinsulinemia rather than insulin resistance itself induces blood pressure elevation in high fat diet-fed rats. Clin Exp Hypertens 2020; 42:614-621. [PMID: 32349626 DOI: 10.1080/10641963.2020.1756316] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
OBJECTIVE To investigate if insulin resistance per se or the accompanying hyperinsulinemia induced hypertension and its underlying mechanisms. METHODS Sprague-Dawley rats were randomized into normal diet-fed group (ND group) and high-fat diet-fed group (HFD group). Then, the HFD group was further randomly divided into the control group (HFD_C group), the PIO group (treated with pioglitazone), the STZ_DM group (to induce diabetes with streptozotocin) and the DM+Ins group (streptozotocin injection followed by insulin treatment). Insulin sensitivity, plasma insulin, endothelin-1, norepinephrine, aldosterone, angiotensinⅡ and 24-h urinary sodium excretion (USE) levels of the groups were measured and analyzed. A multiple stepwise regression analysis method was applied to exam our hypothesis. RESULTS Compared to HFD_C group, the groups with lower plasma insulin, the PIO group and STZ_DM group, showed higher USE and lower blood pressure. The groups with higher plasma insulin (but same level of insulin resistance), the HFD_C group and DM+Ins group, showed lower USE and higher blood pressure. The 24-h urinary sodium excretion was the most important contributor to the significant changes of blood pressure with an R2 of 25.2% in this animal experiment. CONCLUSIONS It is the compensatory hyperinsulinemia rather than insulin resistance per se that causes blood pressure elevation. The urinary sodium excretion is the key mediator among the multiple mechanisms. Therapies targeting hyperinsulinemia and restricting salt intake may favor a better control of hypertension associated with insulin resistance.
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Affiliation(s)
- Hui Wang
- Department of Endocrinology, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College , Beijing, China
| | - Yaqiang Tian
- Department of Endocrinology, Liaocheng People's Hospital , Liaocheng, Shandong Province, China
| | - Yanyan Chen
- Department of Endocrinology, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College , Beijing, China
| | - Xiaoxia Shen
- Department of Endocrinology, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College , Beijing, China
| | - Lin Pan
- Department of Endocrinology, China-Japan Friendship Hospital , Beijing, China
| | - Guangwei Li
- Department of Endocrinology, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College , Beijing, China.,Department of Endocrinology, China-Japan Friendship Hospital , Beijing, China
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Abstract
The prevalence of obesity-related hypertension is high worldwide and has become a major health issue. The mechanisms by which obesity relates to hypertensive disease are still under intense research scrutiny, and include altered hemodynamics, impaired sodium homeostasis, renal dysfunction, autonomic nervous system imbalance, endocrine alterations, oxidative stress and inflammation, and vascular injury. Most of these contributing factors interact with each other at multiple levels. Thus, as a multifactorial and complex disease, obesity-related hypertension should be recognized as a distinctive form of hypertension, and specific considerations should apply in planning therapeutic approaches to treat obese individuals with high blood pressure.
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Affiliation(s)
- Dinko Susic
- Hypertension Research Laboratory, Ochsner Clinic Foundation, 1514 Jefferson Highway New Orleans, Louisiana 70121, USA
| | - Jasmina Varagic
- Hypertension & Vascular Research, Department of Surgery, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, North Carolina 27157, USA; Department of Physiology and Pharmacology, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, North Carolina 27157, USA.
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Sufiun A, Rafiq K, Fujisawa Y, Rahman A, Mori H, Nakano D, Kobori H, Ohmori K, Masaki T, Kohno M, Nishiyama A. Effect of dipeptidyl peptidase-4 inhibition on circadian blood pressure during the development of salt-dependent hypertension in rats. Hypertens Res 2015; 38:237-43. [PMID: 25588850 DOI: 10.1038/hr.2014.173] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 09/17/2014] [Accepted: 09/20/2014] [Indexed: 01/02/2023]
Abstract
A growing body of evidence has indicated that dipeptidyl peptidase-4 (DPP-4) inhibitors have antihypertensive effects. Here, we aim to examine the effect of vildagliptin, a DPP-4-specific inhibitor, on blood pressure and its circadian-dipping pattern during the development of salt-dependent hypertension in Dahl salt-sensitive (DSS) rats. DSS rats were treated with a high-salt diet (8% NaCl) plus vehicle or vildagliptin (3 or 10 mg kg(-1) twice daily by oral gavage) for 7 days. Blood pressure was measured by the telemetry system. High-salt diet for 7 days significantly increased the mean arterial pressure (MAP), systolic blood pressure (SBP) and were also associated with an extreme dipping pattern of blood pressure in DSS rats. Treatment with vildagliptin dose-dependently decreased plasma DPP-4 activity, increased plasma glucagon-like peptide 1 (GLP-1) levels and attenuated the development of salt-induced hypertension. Furthermore, vildagliptin significantly increased urine sodium excretion and normalized the dipping pattern of blood pressure. In contrast, intracerebroventricular infusion of vildagliptin (50, 500 or 2500 μg) did not alter MAP and heart rate in DSS rats. These data suggest that salt-dependent hypertension initially develops with an extreme blood pressure dipping pattern. The DPP-4 inhibitor, vildagliptin, may elicit beneficial antihypertensive effects, including the improvement of abnormal circadian blood pressure pattern, by enhancing urinary sodium excretion.
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Affiliation(s)
- Abu Sufiun
- Department of Pharmacology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Kazi Rafiq
- Department of Pharmacology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Yoshihide Fujisawa
- Life Science Research Center, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Asadur Rahman
- Department of Pharmacology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Hirohito Mori
- Department of Gastroenterology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Daisuke Nakano
- Department of Pharmacology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Hiroyuki Kobori
- Department of Pharmacology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Koji Ohmori
- Cardiorenal and Cerebrovascular Medicine, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Tsutomu Masaki
- Department of Gastroenterology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Masakazu Kohno
- Cardiorenal and Cerebrovascular Medicine, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Akira Nishiyama
- Department of Pharmacology, Faculty of Medicine, Kagawa University, Kagawa, Japan
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Quadri S, Prathipati P, Jackson DW, Jackson KE. Haemodynamic consequences of recurrent insulin-induced hypoglycaemia. Clin Exp Pharmacol Physiol 2013; 41:81-8. [DOI: 10.1111/1440-1681.12183] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Revised: 09/25/2013] [Accepted: 09/25/2013] [Indexed: 11/30/2022]
Affiliation(s)
- Syed Quadri
- Department of Basic Pharmaceutical Sciences; College of Pharmacy; The University of Louisiana at Monroe; Monroe LA USA
| | - Priyanka Prathipati
- Department of Basic Pharmaceutical Sciences; College of Pharmacy; The University of Louisiana at Monroe; Monroe LA USA
| | - Debra W Jackson
- Department of Biology; The University of Louisiana at Monroe; Monroe LA USA
| | - Keith E Jackson
- Department of Basic Pharmaceutical Sciences; College of Pharmacy; The University of Louisiana at Monroe; Monroe LA USA
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Nguy L, Johansson ME, Grimberg E, Lundgren J, Teerlink T, Carlström M, Lundberg JO, Nilsson H, Guron G. Rats with adenine-induced chronic renal failure develop low-renin, salt-sensitive hypertension and increased aortic stiffness. Am J Physiol Regul Integr Comp Physiol 2013; 304:R744-52. [DOI: 10.1152/ajpregu.00562.2012] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Rats with adenine-induced chronic renal failure (A-CRF) develop metabolic and cardiovascular abnormalities resembling those in patients with chronic kidney disease. The aim of this study was to investigate the mechanisms of hypertension in this model and to assess aortic stiffness in vivo. Male Sprague-Dawley rats were equipped with radiotelemetry probes for arterial pressure recordings and received either chow containing adenine or normal control diet. At 7 to 11 wk after study start, blood pressure responses to high NaCl (4%) diet and different pharmacological interventions were analyzed. Aortic pulse wave velocity was measured under isoflurane anesthesia. Baseline 24-h mean arterial pressure (MAP) was 101 ± 10 and 119 ± 9 mmHg in controls and A-CRF animals, respectively ( P < 0.01). After 5 days of a high-NaCl diet, MAP had increased by 24 ± 6 mmHg in A-CRF animals vs. 2 ± 1 mmHg in controls ( P < 0.001). Candesartan (10 mg/kg by gavage) produced a more pronounced reduction of MAP in controls vs. A-CRF animals (−12 ± 3 vs. −5 ± 5 mmHg, P < 0.05). Aortic pulse wave velocity was elevated in A-CRF rats (5.10 ± 0.51 vs. 4.58 ± 0.17 m/s, P < 0.05). Plasma levels of creatinine were markedly elevated in A-CRF animals (259 ± 46 vs. 31 ± 2 μM, P < 0.001), whereas plasma renin activity was suppressed (0.6 ± 0.5 vs. 12.3 ± 7.3 μg·l−1·h−1, P < 0.001). In conclusion, hypertension in A-CRF animals is characterized by low plasma renin activity and is aggravated by high-NaCl diet, suggesting a pathogenic role for sodium retention and hypervolemia probably secondary to renal insufficiency. Additionally, aortic stiffness was elevated in A-CRF animals as indicated by increased aortic pulse wave velocity.
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Affiliation(s)
- Lisa Nguy
- Department of Molecular and Clinical Medicine/Nephrology, Institute of Medicine, Sahlgrenska Academy at the University of Gothenburg, Sweden
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Sweden
| | - Maria E. Johansson
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Sweden
| | - Elisabeth Grimberg
- Department of Molecular and Clinical Medicine/Nephrology, Institute of Medicine, Sahlgrenska Academy at the University of Gothenburg, Sweden
| | - Jaana Lundgren
- Department of Molecular and Clinical Medicine/Nephrology, Institute of Medicine, Sahlgrenska Academy at the University of Gothenburg, Sweden
| | - Tom Teerlink
- Department of Clinical Chemistry, VU University Medical Centre, Amsterdam, The Netherlands; and
| | - Mattias Carlström
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Jon O. Lundberg
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Holger Nilsson
- Department of Physiology, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Sweden
| | - Gregor Guron
- Department of Molecular and Clinical Medicine/Nephrology, Institute of Medicine, Sahlgrenska Academy at the University of Gothenburg, Sweden
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Nielsen FT, Jensen BL, Hansen PBL, Marcussen N, Bie P. The mineralocorticoid receptor antagonist eplerenone reduces renal interstitial fibrosis after long-term cyclosporine treatment in rat: antagonizing cyclosporine nephrotoxicity. BMC Nephrol 2013; 14:42. [PMID: 23425330 PMCID: PMC3602207 DOI: 10.1186/1471-2369-14-42] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Accepted: 01/31/2013] [Indexed: 11/10/2022] Open
Abstract
Background Chronic cyclosporine-(CsA)-mediated loss of kidney function is a major clinical problem in organ transplantation. We hypothesized that the mineralocorticoid receptor antagonist eplerenone (EPL) prevents chronic CsA-induced renal interstitial volume increase, tubule loss, and functional impairment in a rat model. Methods Sprague–Dawley rats received CsA alone (15 mg/kg/d p.o.), CsA and EPL (approximately 100 mg/kg/day p.o.) or vehicle (control) for 12 weeks. At 11 weeks, chronic indwelling arterial and venous catheters were implanted for continuous measurements of arterial blood pressure (BP) and GFR (inulin clearance) in conscious, freely moving animals. Plasma was sampled for analysis and kidney tissue was fixed for quantitative stereological analyses. Results Compared to controls, CsA-treatment reduced relative tubular volume (0.73±0.03 vs. 0.85±0.01, p<0.05) and increased relative interstitial volume (0.080±0.004 vs. 0.045±0.003, p<0.05); EPL attenuated these changes (0.82±0.02, p<0.05, and 0.060±0.006, p<0.05, respectively). CsA-treated rats had more sclerotic glomeruli and a higher degree of vascular depositions in arterioles; both were significantly reduced in CsA+EPL-treated animals. CsA increased BP and reduced body weight gain and GFR. In CsA+EPL rats, weight gain, GFR and BP at rest (daytime) were normalized; however, BP during activity (night) remained elevated. Plasma sodium and potassium concentrations, kidney-to-body weight ratios and CsA whole blood concentration were similar in CsA and CsA+EPL rats. Conclusions It is concluded that in the chronic cyclosporine rat nephropathy model, EPL reduces renal tissue injury, hypofiltration, hypertension, and growth impairment. MR antagonists should be tested for their renoprotective potential in patients treated with calcineurin inhibitors.
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Affiliation(s)
- Finn Thomsen Nielsen
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Winsløwparken 21, 3, Odense C, DK-5000, Denmark.
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Nguy L, Nilsson H, Lundgren J, Johansson ME, Teerlink T, Scheffer PG, Guron G. Vascular function in rats with adenine-induced chronic renal failure. Am J Physiol Regul Integr Comp Physiol 2012; 302:R1426-35. [PMID: 22513744 DOI: 10.1152/ajpregu.00696.2011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The aim of the present study was to characterize the function of resistance arteries, and the aorta, in rats with adenine-induced chronic renal failure (A-CRF). Sprague-Dawley rats were randomized to chow with or without adenine supplementation. After 6-10 wk, mesenteric arteries and thoracic aortas were analyzed ex vivo by wire myography. Plasma creatinine concentrations were elevated twofold at 2 wk, and eight-fold at the time of death in A-CRF animals. Ambulatory systolic and diastolic blood pressures measured by radiotelemetry were significantly elevated in A-CRF animals from week 3 and onward. At death, A-CRF animals had anemia, hyperphosphatemia, hyperparathyroidism, and elevated plasma levels of asymmetric dimethylarginine and oxidative stress markers. There were no significant differences between groups in the sensitivity, or maximal response, to ACh, sodium nitroprusside (SNP), norepinephrine, or phenylephrine in either mesenteric arteries or aortas. However, in A-CRF animals, the rate of aortic relaxation was significantly reduced following washout of KCl (both in intact and endothelium-denuded aorta) and in response to ACh and SNP. Also the rate of contraction in response to KCl was significantly reduced in A-CRF animals both in mesenteric arteries and aortas. The media of A-CRF aortas was thickened and showed focal areas of fragmented elastic lamellae and disorganized smooth muscle cells. No vascular calcifications could be detected. These results indicate that severe renal failure for a duration of less than 10 wk in this model primarily affects the aorta and mainly slows the rate of relaxation.
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Affiliation(s)
- Lisa Nguy
- Department of Molecular and Clinical Medicine/Nephrology, Institute of Medicine, Sahlgrenska Academy at University of Gothenburg, Sweden.
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Abstract
Obesity-related hypertension is increasingly recognized as a distinct hypertensive phenotype requiring a modified approach to diagnosis and management. In this review rapidly evolving insights into the complex and interdependent mechanisms linking obesity to hypertension are discussed. Overweight and obesity are associated with adipose tissue dysfunction, characterized by enlarged hypertrophied adipocytes, increased infiltration by macrophages and marked changes in secretion of adipokines and free fatty acids. This results in chronic vascular inflammation, oxidative stress, activation of the renin-angiotensin-aldosterone system and sympathetic overdrive, eventually leading to hypertension. These mechanisms may provide novel targets for anti-hypertensive drug treatment. Recognition of obesity-related hypertension as a distinct diagnosis enables tailored therapy in clinical practice. This includes lifestyle modification and accommodated choice of blood pressure-lowering drugs.
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Affiliation(s)
- J A N Dorresteijn
- Department of Vascular Medicine, University Medical Center Utrecht, Utrecht, The Netherlands
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Belin de Chantemèle EJ, Muta K, Mintz J, Tremblay ML, Marrero MB, Fulton DJ, Stepp DW. Protein tyrosine phosphatase 1B, a major regulator of leptin-mediated control of cardiovascular function. Circulation 2009; 120:753-63. [PMID: 19687357 DOI: 10.1161/circulationaha.109.853077] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Obesity causes hypertension and sympathoactivation, a process proposed to be mediated by leptin. Protein tyrosine phosphatase 1B (PTP1B), a major new pharmaceutical target in the treatment of obesity and type II diabetes mellitus, constrains the metabolic actions of leptin, but the extent to which PTP1B regulates its cardiovascular effects is unclear. This study examined the hypothesis that PTP1B is a negative regulator of the cardiovascular effects of leptin. METHODS AND RESULTS PTP1B knockout mice had lower body fat but higher mean arterial pressure (116+/-5 versus 105+/-5 mm Hg, P<0.05) than controls. Leptin infusion produced a greater anorexic effect in PTP1B knockout mice and a marked increase in mean arterial pressure (135+/-5 mm Hg) in PTP1B knockout mice only. The decrease in mean arterial pressure in response to ganglionic blockade was higher in PTP1B knockout mice (-38+/-3% versus -29+/-3%, P<0.05), which suggests increased sympathetic tone. PTP1B deletion blunted mean arterial pressure responses to phenylephrine injection (55+/-10% versus 93+/-7%, P<0.05). Phenylephrine-induced aortic contraction was reduced in PTP1B knockout mice (57.7+/-9% versus 96.3+/-12% of KCl, P<0.05), consistent with desensitization to chronically elevated sympathetic tone. Furthermore, PTP1B deletion significantly reduced gene expression of 3 alpha(1)-adrenergic receptor subtypes, consistent with blunted constriction to phenylephrine. CONCLUSIONS These data indicate that PTP1B is a key regulator of the cardiovascular effects of leptin and that reduced vascular adrenergic reactivity provides a compensatory limit to the effects of leptin on mean arterial pressure.
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The role of obesity in the pathogenesis of hypertension. ACTA ACUST UNITED AC 2008; 5:101-11. [DOI: 10.1038/ncpneph1022] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2008] [Accepted: 11/17/2008] [Indexed: 02/01/2023]
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