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Chohnan S, Matsuno S, Shimizu K, Tokutake Y, Kohari D, Toyoda A. Coenzyme A and Its Thioester Pools in Obese Zucker and Zucker Diabetic Fatty Rats. Nutrients 2020; 12:E417. [PMID: 32041091 PMCID: PMC7071249 DOI: 10.3390/nu12020417] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 02/03/2020] [Accepted: 02/03/2020] [Indexed: 12/29/2022] Open
Abstract
Feeding behavior is closely related to hypothalamic malonyl-CoA level in the brain and diet-induced obesity affects total CoA pools in liver. Herein, we performed a comprehensive analysis of the CoA pools formed in thirteen tissues of Zucker and Zucker diabetic fatty (ZDF) rats. Hypothalamic malonyl-CoA levels in obese rats remained low and were almost the same as those of lean rats, despite obese rats having much higher content of leptin, insulin, and glucose in their sera. Regardless of the fa-genotypes, larger total CoA pools were formed in the livers of ZDF rats and the size of hepatic total CoA pools in Zucker rats showed almost one tenth of the size of ZDF rats. The decreased total CoA pool sizes in Zucker rats was observed in the brown adipose tissues, while ZDF-fatty rats possessed 6% of total CoA pool in the lean rats in response to fa deficiency. This substantially lower CoA content in the obese rats would be disadvantageous to non-shivering thermogenesis. Thus, comparing the intracellular CoA behaviors between Zucker and ZDF rats, as well as the lean and fatty rats of each strain would help to elucidate features of obesity and type 2 diabetes in combination with result (s) of differential gene expression analysis and/or comparative genomics.
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Affiliation(s)
- Shigeru Chohnan
- Department of Food and Life Sciences, Ibaraki University College of Agriculture, 3-21-1 Chuo, Ami, Ibaraki 300-0393, Japan; (S.M.); (K.S.); (D.K.); (A.T.)
| | - Shiori Matsuno
- Department of Food and Life Sciences, Ibaraki University College of Agriculture, 3-21-1 Chuo, Ami, Ibaraki 300-0393, Japan; (S.M.); (K.S.); (D.K.); (A.T.)
| | - Kei Shimizu
- Department of Food and Life Sciences, Ibaraki University College of Agriculture, 3-21-1 Chuo, Ami, Ibaraki 300-0393, Japan; (S.M.); (K.S.); (D.K.); (A.T.)
| | - Yuka Tokutake
- Department of Applied Life Science, United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai, Fuchu, Tokyo 183-8509, Japan;
| | - Daisuke Kohari
- Department of Food and Life Sciences, Ibaraki University College of Agriculture, 3-21-1 Chuo, Ami, Ibaraki 300-0393, Japan; (S.M.); (K.S.); (D.K.); (A.T.)
| | - Atsushi Toyoda
- Department of Food and Life Sciences, Ibaraki University College of Agriculture, 3-21-1 Chuo, Ami, Ibaraki 300-0393, Japan; (S.M.); (K.S.); (D.K.); (A.T.)
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Rossi R, Ciofalo M. Current Advances in the Synthesis and Biological Evaluation of Pharmacologically Relevant 1,2,4,5-Tetrasubstituted-1H-Imidazole Derivatives. CURR ORG CHEM 2019. [DOI: 10.2174/1385272823666191014154129] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
:
In recent years, the synthesis and evaluation of the
biological properties of 1,2,4,5-tetrasubstituted-1H-imidazole
derivatives have been the subject of a large number of studies
by academia and industry. In these studies it has been shown
that this large and highly differentiated class of heteroarene
derivatives includes high valuable compounds having important
biological and pharmacological properties such as
antibacterial, antifungal, anthelmintic, anti-inflammatory, anticancer,
antiviral, antihypertensive, cholesterol-lowering, antifibrotic,
antiuricemic, antidiabetic, antileishmanial and antiulcer
activities.
:
The present review with 411 references, in which we focused on the literature data published mainly from 2011
to 2017, aims to update the readers on the recent developments on the synthesis and biological evaluation of
pharmacologically relevant 1,2,4,5-tetrasubstituted-1H-imidazole derivatives with an emphasis on their different
molecular targets and their potential use as drugs to treat various types of diseases. Reference was also
made to substantial literature data acquired before 2011 in this burgeoning research area.
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Affiliation(s)
- Renzo Rossi
- Dipartimento di Chimica e Chimica Industriale, University of Pisa - via Moruzzi, 3, I-56124 Pisa, Italy
| | - Maurizio Ciofalo
- Dipartimento di Scienze Agrarie, Alimentari e Forestali, University of Palermo - Viale delle Scienze, Edificio 4, I-90128 Palermo, Italy
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Zhu Y, Li ZL, Ding A, Yang H, Zhu WP, Cui TX, Zhang HT, Zhang H. Olmesartan Medoxomil, An Angiotensin II-Receptor Blocker, Ameliorates Renal Injury In db/db Mice. DRUG DESIGN DEVELOPMENT AND THERAPY 2019; 13:3657-3667. [PMID: 31695333 PMCID: PMC6815789 DOI: 10.2147/dddt.s217826] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 09/13/2019] [Indexed: 01/13/2023]
Abstract
Background Diabetic nephropathy (DN) is a common complication of diabetes mellitus (DM) and also a major cause of end-stage renal disease (ESRD). Olmesartan medoxomil (OM) is an angiotensin II receptor blocker (ARB) and has been shown to exhibit renoprotective effects on a streptozotocin (STZ)-induced diabetic rat model. Yet, whether OM affects DN progression and renal injury in db/db mice, a type 2 diabetic murine model, has not been established. Methods Wild-type (n = 15) and db/db mice (n = 15) were treated with control saline or OM via oral gavage. The physiological and biochemical parameters were evaluated and histological examinations of kidney specimens were performed. Results Compared with saline-treated db/db mice, db/db mice administered with OM showed ameliorated diabetic physiological and biochemical parameters. In addition, OM decreased urinary albumin excretion and plasma creatinine level in db/db mice. Moreover, histologically, OM reduced glomerular hypertrophy and injury, and also ameliorated tubular injury, thus suggesting that OM improves renal function and minimizes renal pathological deterioration in db/db mice. Conclusion Our study reveals a beneficial role of OM in ameliorating DN in db/db mice, which is associated with its renoprotective function.
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Affiliation(s)
- Ye Zhu
- Department of Nephrology, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai 519000, People's Republic of China
| | - Ze-Liang Li
- Department of Medical Imaging, Cangzhou Hospital of Integrated Traditional Chinese Medicine-Western Medicine, Cangzhou 061001, People's Republic of China
| | - Ao Ding
- Department of Nephrology, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai 519000, People's Republic of China
| | - Hui Yang
- Department of Rheumatology, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai 519000, People's Republic of China
| | - Wei-Ping Zhu
- Department of Nephrology, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai 519000, People's Republic of China
| | - Tong-Xia Cui
- Department of Nephrology, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai 519000, People's Republic of China
| | - Hui-Tao Zhang
- Center for Interventional Medicine, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai 519000, People's Republic of China
| | - Hua Zhang
- Department of Nephrology, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai 519000, People's Republic of China
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Fakhruddin S, Alanazi WA, Alhamami HN, Briski KP, Jackson KE. Hyperglycaemia induced by chronic i.p. and oral glucose loading leads to hypertension through increased Na + retention in proximal tubule. Exp Physiol 2018; 103:236-249. [PMID: 29114945 DOI: 10.1113/ep086604] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 11/03/2017] [Indexed: 12/11/2022]
Abstract
NEW FINDINGS What is the central question of the study? Chronic glucose feeding accompanied by glucose injection (i.p.) causes sustained hyperglycaemia and hypertension in rats. The exact reason for the hypertension is not known. We explore some molecular pathways of the renal proximal tubule that might promote Na+ retention. What is the main finding and its importance? Development of hypertension was mediated by upregulation of the renal renin-angiotensin system and oxidative stress, acting via the Na+ -K+ -ATPase α1 -subunit in the proximal tubule, which appears to pump intracellular Na+ into the extracellular space, increasing Na+ reabsorption and blood pressure. Targeting the Na+ -K+ -ATPase α1 -subunit might provide a therapeutic strategy for treatment of hypertension. Feeding animals glucose-, fructose-, sucrose- and fat-enriched diets can lead to diet-induced hyperglycaemia, the severity of which largely depends on the types and concentrations of the nutrients used and duration of the dietary intervention. As a dietary intervention strategy, we adopted glucose-enriched diet and drinking water, with i.p. glucose injection at a dose previously determined to be effective to establish a sustained hyperglycaemia over a period of 2 weeks. We used four groups of Sprague-Dawley rats: control; glucose treated; glucose plus tempol treated; and glucose plus captopril treated. Blood glucose concentrations started to increase gradually from day 3, peaked (321 mg dl-1 ) at day 12 and remained at similar levels until the end of the study on day 14 in the glucose treated-group compared with the control group. In contrast, the tempol- and captopril-treated groups showed significantly high glucose concentrations only in the second week. The plasma insulin concentration was significantly increased in glucose-treated animals but not in tempol- and captopril-treated groups when compared with the control rats. We also observed elevated blood pressure in the glucose-treated group compared with the control group, which can be attributed to the increase in angiotensin II concentrations from 46.67 to 99 pg ml-1 (control versus glucose), increased oxidative stress in the cortical proximal tubule (PT), decreased urine flow, and increased expression and activity of the PT-specific α1 -subunit of Na+ -K+ -ATPase in the renal cortex, which is responsible for increased sodium reabsorption from epithelial cells of PT into the peritubular capillaries, leading to increased blood volume and eventual blood pressure. All these events were reversed in captopril- and tempol-treated animals.
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Affiliation(s)
- Selim Fakhruddin
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, University of Louisiana at Monroe (ULM), Monroe, LA, USA
| | - Wael A Alanazi
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, University of Louisiana at Monroe (ULM), Monroe, LA, USA
| | - Hussain N Alhamami
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, University of Louisiana at Monroe (ULM), Monroe, LA, USA
| | - Karen P Briski
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, University of Louisiana at Monroe (ULM), Monroe, LA, USA
| | - Keith E Jackson
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, University of Louisiana at Monroe (ULM), Monroe, LA, USA
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Abstract
The gastrointestinal alterations associated with the consumption of an obesogenic diet, such as inflammation, permeability impairment and oxidative stress, have been poorly explored in both diet-induced obesity (DIO) and genetic obesity. The aim of the present study was to examine the impact of an obesogenic diet on the gut health status of DIO rats in comparison with the Zucker (fa/fa) rat leptin receptor-deficient model of genetic obesity over time. For this purpose, female Wistar rats (n 48) were administered a standard or a cafeteria diet (CAF diet) for 12, 14·5 or 17 weeks and were compared with fa/fa Zucker rats fed a standard diet for 10 weeks. Morphometric variables, plasma biochemical parameters, myeloperoxidase (MPO) activity and reactive oxygen species (ROS) levels in the ileum were assessed, as well as the expressions of proinflammatory genes (TNF-α and inducible nitric oxide synthase (iNOS)) and intestinal permeability genes (zonula occludens-1, claudin-1 and occludin). Both the nutritional model and the genetic obesity model showed increased body weight and metabolic alterations at the final time point. An increase in intestinal ROS production and MPO activity was observed in the gastrointestinal tracts of rats fed a CAF diet but not in the genetic obesity model. TNF-α was overexpressed in the ileum of both CAF diet and fa/fa groups, and ileal inflammation was associated with the degree of obesity and metabolic alterations. Interestingly, the 17-week CAF group and the fa/fa rats exhibited alterations in the expressions of permeability genes. Relevantly, in the hyperlipidic refined sugar diet model of obesity, the responses to chronic energy overload led to time-dependent increases in gut inflammation and oxidative stress.
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Minas JN, Thorwald MA, Conte D, Vázquez-Medina JP, Nishiyama A, Ortiz RM. Angiotensin and mineralocorticoid receptor antagonism attenuates cardiac oxidative stress in angiotensin II-infused rats. Clin Exp Pharmacol Physiol 2016; 42:1178-88. [PMID: 26234762 DOI: 10.1111/1440-1681.12473] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Revised: 06/30/2015] [Accepted: 06/30/2015] [Indexed: 11/30/2022]
Abstract
Angiotensin II (Ang II) and aldosterone contribute to hypertension, oxidative stress and cardiovascular damage, but the contributions of aldosterone during Ang II-dependent hypertension are not well defined because of the difficulty to assess each independently. To test the hypothesis that during Ang II infusion, oxidative and nitrosative damage is mediated through both the mineralocorticoid receptor (MR) and angiotensin type 1 receptor (AT1), five groups of Sprague-Dawley rats were studied: (i) control; (ii) Ang II infused (80 ng/min × 28 days); (iii) Ang II + AT1 receptor blocker (ARB; 10 mg losartan/kg per day × 21 days); (iv) Ang II + mineralocorticoid receptor (MR) antagonist (Epl; 100 mg eplerenone/day × 21 days); and (v) Ang II + ARB + Epl (Combo; × 21 days). Both ARB and combination treatments completely alleviated the Ang II-induced hypertension, whereas eplerenone treatment only prolonged the onset of the hypertension. Eplerenone treatment exacerbated the Ang II-mediated increase in plasma and heart aldosterone 2.3- and 1.8-fold, respectively, while ARB treatment reduced both. Chronic MR blockade was sufficient to ameliorate the AT1-mediated increase in oxidative damage. All treatments normalized protein oxidation (nitrotyrosine) levels; however, only ARB and Combo treatments completely reduced lipid peroxidation (4-hydroxynonenal) to control levels. Collectively, these data suggest that receptor signalling, and not the elevated arterial blood pressure, is the principal culprit in the oxidative stress-associated cardiovascular damage in Ang II-dependent hypertension.
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Affiliation(s)
- Jacqueline N Minas
- Molecular Cell Biology, School of Natural Sciences, University of California, Merced, CA, USA
| | - Max A Thorwald
- Molecular Cell Biology, School of Natural Sciences, University of California, Merced, CA, USA
| | - Debra Conte
- Molecular Cell Biology, School of Natural Sciences, University of California, Merced, CA, USA
| | | | - Akira Nishiyama
- Department of Pharmacology, Kagawa Medical University, Kagawa, Japan
| | - Rudy M Ortiz
- Molecular Cell Biology, School of Natural Sciences, University of California, Merced, CA, USA
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Sharaf El-Din AAI, Abd Allah OM. Impact of Olmesartan Medoxomil on Amiodarone-Induced Pulmonary Toxicity in Rats: Focus on Transforming Growth Factor-ß1. Basic Clin Pharmacol Toxicol 2016; 119:58-67. [DOI: 10.1111/bcpt.12551] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2015] [Accepted: 12/23/2015] [Indexed: 12/18/2022]
Affiliation(s)
| | - Omaima M. Abd Allah
- Department of Pharmacology and Therapeutics; Faculty of Medicine; Benha University; Benha Egypt
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Ito D, Cao P, Kakihana T, Sato E, Suda C, Muroya Y, Ogawa Y, Hu G, Ishii T, Ito O, Kohzuki M, Kiyomoto H. Chronic Running Exercise Alleviates Early Progression of Nephropathy with Upregulation of Nitric Oxide Synthases and Suppression of Glycation in Zucker Diabetic Rats. PLoS One 2015; 10:e0138037. [PMID: 26379244 PMCID: PMC4574951 DOI: 10.1371/journal.pone.0138037] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 08/24/2015] [Indexed: 11/19/2022] Open
Abstract
Exercise training is known to exert multiple beneficial effects including renal protection in type 2 diabetes mellitus and obesity. However, the mechanisms regulating these actions remain unclear. The present study evaluated the effects of chronic running exercise on the early stage of diabetic nephropathy, focusing on nitric oxide synthase (NOS), oxidative stress and glycation in the kidneys of Zucker diabetic fatty (ZDF) rats. Male ZDF rats (6 weeks old) underwent forced treadmill exercise for 8 weeks (Ex-ZDF). Sedentary ZDF (Sed-ZDF) and Zucker lean (Sed-ZL) rats served as controls. Exercise attenuated hyperglycemia (plasma glucose; 242 ± 43 mg/dL in Sed-ZDF and 115 ± 5 mg/dL in Ex-ZDF) with increased insulin secretion (plasma insulin; 2.3 ± 0.7 and 5.3 ± 0.9 ng/mL), reduced albumin excretion (urine albumin; 492 ± 70 and 176 ± 11 mg/g creatinine) and normalized creatinine clearance (9.7 ± 1.4 and 4.5 ± 0.8 mL/min per body weight) in ZDF rats. Endothelial (e) and neuronal (n) NOS expression in kidneys of Sed-ZDF rats were lower compared with Sed-ZL rats (p<0.01), while both eNOS and nNOS expression were upregulated by exercise (p<0.01). Furthermore, exercise decreased NADPH oxidase activity, p47phox expression (p<0.01) and α-oxoaldehydes (the precursors for advanced glycation end products) (p<0.01) in the kidneys of ZDF rats. Additionally, morphometric evidence indicated renal damage was reduced in response to exercise. These data suggest that upregulation of NOS expression, suppression of NADPH oxidase and α-oxoaldehydes in the kidneys may, at least in part, contribute to the renal protective effects of exercise in the early progression of diabetic nephropathy in ZDF rats. Moreover, this study supports the theory that chronic aerobic exercise could be recommended as an effective non-pharmacological therapy for renoprotection in the early stages of type 2 diabetes mellitus and obesity.
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Affiliation(s)
- Daisuke Ito
- Department of Miyagi Community Health Promotion, Tohoku University Graduate School of Medicine, Tohoku University, Sendai, Japan
- Department of Internal Medicine and Rehabilitation Science, Tohoku University Graduate School of Medicine, Tohoku University, Sendai, Japan
- * E-mail:
| | - Pengyu Cao
- Department of Internal Medicine and Rehabilitation Science, Tohoku University Graduate School of Medicine, Tohoku University, Sendai, Japan
| | - Takaaki Kakihana
- Department of Internal Medicine and Rehabilitation Science, Tohoku University Graduate School of Medicine, Tohoku University, Sendai, Japan
| | - Emiko Sato
- Department of Clinical Pharmacology and Therapeutics, Tohoku University Graduate School of Pharmaceutical Sciences and Medicine, Tohoku University, Sendai, Japan
| | - Chihiro Suda
- Department of Internal Medicine and Rehabilitation Science, Tohoku University Graduate School of Medicine, Tohoku University, Sendai, Japan
| | - Yoshikazu Muroya
- Department of Internal Medicine and Rehabilitation Science, Tohoku University Graduate School of Medicine, Tohoku University, Sendai, Japan
| | - Yoshiko Ogawa
- Department of Internal Medicine and Rehabilitation Science, Tohoku University Graduate School of Medicine, Tohoku University, Sendai, Japan
| | - Gaizun Hu
- Department of Internal Medicine and Rehabilitation Science, Tohoku University Graduate School of Medicine, Tohoku University, Sendai, Japan
| | - Tadashi Ishii
- Department of Miyagi Community Health Promotion, Tohoku University Graduate School of Medicine, Tohoku University, Sendai, Japan
| | - Osamu Ito
- Department of Internal Medicine and Rehabilitation Science, Tohoku University Graduate School of Medicine, Tohoku University, Sendai, Japan
| | - Masahiro Kohzuki
- Department of Internal Medicine and Rehabilitation Science, Tohoku University Graduate School of Medicine, Tohoku University, Sendai, Japan
| | - Hideyasu Kiyomoto
- Department of Miyagi Community Health Promotion, Tohoku University Graduate School of Medicine, Tohoku University, Sendai, Japan
- Department of Integrated Nephrology and Telemedicine, Tohoku Medical Megabank Organization, Tohoku University, Sendai, Japan
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Effect of orally administered L. fermentum NCIMB 5221 on markers of metabolic syndrome: an in vivo analysis using ZDF rats. Appl Microbiol Biotechnol 2014; 98:115-26. [PMID: 24121931 DOI: 10.1007/s00253-013-5252-8] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 09/05/2013] [Accepted: 09/07/2013] [Indexed: 02/06/2023]
Abstract
Metabolic syndrome, encompassing type 2 diabetes mellitus and cardiovascular disease, is a growing health concern of industrialized countries. Ferulic acid (FA) is a phenolic acid found in foods normally consumed by humans that has demonstrated antioxidant activity, cholesterol-lowering capabilities, and anti-tumorigenic properties. Select probiotic bacteria, including Lactobacillus fermentum NCIMB 5221, produce FA due to intrinsic ferulic acid esterase activity. The aim of the present research was to investigate a FA-producing probiotic, L. fermentum NCIMB 5221, as a biotherapeutic for metabolic syndrome. The probiotic formulation was administered daily for 8 weeks to Zucker diabetic fatty (ZDF) rats, a model of hyperlipidemia and hyperglycemia. Results show that the probiotic formulation reduced fasting insulin levels and insulin resistance, significantly reduced serum triglycerides (p = 0.016), lowered serum low-density lipoprotein cholesterol levels (p = 0.008), and significantly reduced the atherogenic (p = 0.016) and atherosclerosis (p = 0.012) index as compared to the control animals. In addition, the probiotic formulation significantly increased high-density lipoprotein cholesterol levels (p = 0.041) as compared to the control animals. This research indicates that administration of the FA-producing L. fermentum NCIMB 5221 has the potential to reduce insulin resistance, hyperinsulinemia, hypercholesterolemia, and other markers involved in the pathogenesis of metabolic syndrome. Further studies are required to investigate the human clinical potential of the probiotic formulation in affecting the markers and pathogenesis of metabolic syndrome.
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Hye Khan MA, Neckář J, Haines J, Imig JD. Azilsartan improves glycemic status and reduces kidney damage in zucker diabetic fatty rats. Am J Hypertens 2014; 27:1087-95. [PMID: 24598210 DOI: 10.1093/ajh/hpu016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Azilsartan medoxomil (AZL-M), an angiotensin II receptor blocker, demonstrates antihypertensive and organ protective effects in hypertension. We investigated the efficacy of AZL-M to ameliorate metabolic syndrome and kidney damage associated with type 2 diabetes using Zucker diabetic fatty (ZDF) rats. METHODS ZDF rats were treated with vehicle or AZL-M for 8 weeks. Zucker diabetic lean (ZDL) rats were used as controls. Urine and plasma samples were collected for biochemical analysis, and kidney tissues were used for histopathological and immunohistopathological examination at the end of the 8-week protocol. RESULTS ZDF rats were diabetic with hyperglycemia and impaired glucose tolerance, and AZL-M ameliorated the diabetic phenotype. ZDF rats were hypertensive compared with ZDL rats (181±6 vs. 129±7mm Hg), and AZL-M decreased blood pressure in ZDF rats (116±7mm Hg). In ZDF rats, there was marked renal damage with elevated proteinuria, albuminuria, nephrinuria, 2-4-fold higher tubular cast formation, and glomerular injury compared with ZDL rats. AZL-M treatment reduced renal damage in ZDF rats. ZDF rats demonstrated renal inflammation and oxidative stress with elevated urinary monocyte chemoattractant protein 1 excretion, renal infiltration of macrophages, and elevated kidney malondialdehyde levels. AZL-M reduced oxidative stress and inflammation in ZDF rats. CONCLUSIONS Overall, we demonstrate that AZL-M attenuates kidney damage in type 2 diabetes. We further demonstrate that anti-inflammatory and antioxidative activities of AZL-M contribute to its kidney protective action.
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Affiliation(s)
- Md Abdul Hye Khan
- Department of Pharmacology & Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Jan Neckář
- Department of Pharmacology & Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin; Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Jasmine Haines
- Department of Pharmacology & Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - John D Imig
- Department of Pharmacology & Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin; Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin.
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Azilsartan Decreases Renal and Cardiovascular Injury in the Spontaneously Hypertensive Obese Rat. Cardiovasc Drugs Ther 2014; 28:313-22. [DOI: 10.1007/s10557-014-6530-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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12
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Greathouse M. Olmesartan medoxomil-based therapy for the management of hypertension. Expert Rev Clin Pharmacol 2014; 1:593-604. [DOI: 10.1586/17512433.1.5.593] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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13
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Ohmura T, Tsunenari I, Seidler R, Chachin M, Hayashi T, Konomi A, Matsumaru T, Sumida T, Hayashi N, Horie Y. Renoprotective effects of telmisartan on renal injury in obese Zucker rats. Acta Diabetol 2012; 49 Suppl 1:S15-24. [PMID: 18008027 DOI: 10.1007/s00592-007-0016-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2007] [Accepted: 08/03/2007] [Indexed: 01/13/2023]
Abstract
The purpose of the present study was to investigate the renoprotective effect of telmisartan, an angiotensin II receptor antagonist, on the early stages of diabetic nephropathy in obese Zucker rats, which is a type 2-related diabetes mellitus model. Telmisartan 1, 3 or 10 mg/kg/day was orally administered to 7-week-old rats that demonstrated glucose tolerance without albuminuria or proteinuria, for 24 consecutive weeks (Experiment A). In another experiment (Experiment B), oral administration of telmisartan 10 mg/kg/day was initiated at the age of 16 weeks after the rats demonstrated marked proteinuria, and continued for 24 weeks. Telmisartan inhibited the increase in proteinuria and albuminuria in a dose-dependent manner, and the inhibition for all telmisartan groups was statistically significant by the completion of administration (Experiment A). Telmisartan also displayed similar inhibitory effects on proteinuria and albuminuria in Experiment B. Histologically, telmisartan [3 and 10 mg/kg/day] was associated with a significant decrease in the progression of glomerulosclerosis, and significantly improved interstitial cell infiltration, interstitial fibrosis and dilation and atrophy of renal tubules. Furthermore, telmisartan treatment was associated with a tendency towards normalized plasma lipids (total cholesterol and triglyceride). Our results suggest that telmisartan has a definite renoprotective effect against renal injury in type II diabetic nephropathy.
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Affiliation(s)
- T Ohmura
- Project Coordination Group, Kawanishi Pharma Research Institute, Nippon Boehringer Ingelheim Co, Ltd, Yato, 3-10-1 Kawanishi, Hyogo, Japan.
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14
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Wang Y, Landheer S, van Gilst WH, van Amerongen A, Hammes HP, Henning RH, Deelman LE, Buikema H. Attenuation of renovascular damage in Zucker diabetic fatty rat by NWT-03, an egg protein hydrolysate with ACE- and DPP4-inhibitory Activity. PLoS One 2012; 7:e46781. [PMID: 23071636 PMCID: PMC3468629 DOI: 10.1371/journal.pone.0046781] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Accepted: 09/06/2012] [Indexed: 12/15/2022] Open
Abstract
Background Dipeptidyl peptidase 4 (DPP4) and angiotensin-converting enzyme (ACE) are important target enzymes in glycemic control and renovascular protection. Here, we studied the effect of NWT-03, an egg protein hydrolysate with DPP4- and ACE-inhibitory activity, on renovascular damage in Zucker diabetic fatty (ZDF) rats. Comparisons were made to rats treated with vildagliptin (VIL), included as a positive control for the effect of DPP4 inhibition. Methods ZDF rats received NWT-03 (1 g/kg/day) or VIL (3 mg/kg/day) from 10 to 25 weeks of age. Metabolic and renal functions were assessed; the kidney was removed for histological analysis of glomerulosclerosis and expression of pro-inflammatory/fibrotic markers (RT-PCR and Western blotting); and the aorta was removed for studies of endothelium-dependent relaxation (EDR). Findings Hyperinsulinemic ZDF rats typically developed signs of type-2 diabetes and renovascular damage, as evidenced by albuminuria, glomerulosclerosis, and impaired EDR. Neither NWT-03 nor VIL improved metabolic parameters; for VIL, this was despite a 5-fold increase in glucagon-like peptide (GLP)-1 levels. NWT-03 and VIL both reduced renal interleukin (Il)-1β/Il-13 mRNA expression and glomerulosclerosis. However, only NWT-03 additionally decreased renal tumor necrosis factor (TNF)-α mRNA and P22phox protein expression, reduced albuminuria, and restored aortic EDR. Indomethacin added to the organ bath instantly improved aortic EDR, indicating a role for cyclooxygenase (COX)-derived contractile prostanoids in opposing relaxation in ZDF rats. This indomethacin effect was reduced by NWT-03, but not by VIL, and coincided with decreased renal COX-1/2 protein expression. Conclusion and Interpretation Long-term supplementation with the egg protein hydrolysate NWT-03 attenuated renovascular damage in this preclinical rat model of type 2 diabetes. A comparison to the DPP4-inhibitor VIL suggests that the effects of NWT-03 were related to both ACE- and DPP4-inhibitory properties. The development of protein hydrolysates with a multiple-targeting strategy may be of benefit to functional food formulations.
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Affiliation(s)
- Yumei Wang
- 5th Medical Department, Section of Endocrinology, University Hospital Mannheim, University of Heidelberg, Mannheim, Germany
| | - Sjoerd Landheer
- Departments of Clinical Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Wiek H. van Gilst
- Department of Cardiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Aart van Amerongen
- Food and Biobased Research, Wageningen University and Research Center, Wageningen, The Netherlands
| | - Hans-Peter Hammes
- 5th Medical Department, Section of Endocrinology, University Hospital Mannheim, University of Heidelberg, Mannheim, Germany
| | - Robert H. Henning
- Departments of Clinical Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Leo E. Deelman
- Departments of Clinical Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Hendrik Buikema
- Departments of Clinical Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
- * E-mail:
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Masuda T, Muto S, Fujisawa G, Iwazu Y, Kimura M, Kobayashi T, Nonaka-Sarukawa M, Sasaki N, Watanabe Y, Shinohara M, Murakami T, Shimada K, Kobayashi E, Kusano E. Heart angiotensin II-induced cardiomyocyte hypertrophy suppresses coronary angiogenesis and progresses diabetic cardiomyopathy. Am J Physiol Heart Circ Physiol 2012; 302:H1871-83. [PMID: 22389386 DOI: 10.1152/ajpheart.00663.2011] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
To examine whether and how heart ANG II influences the coordination between cardiomyocyte hypertrophy and coronary angiogenesis and contributes to the pathogenesis of diabetic cardiomyopathy, we used Spontaneously Diabetic Torii (SDT) rats treated without and with olmesartan medoxomil (an ANG II receptor blocker). In SDT rats, left ventricular (LV) ANG II, but not circulating ANG II, increased at 8 and 16 wk after diabetes onset. SDT rats developed LV hypertrophy and diastolic dysfunction at 8 wk, followed by LV systolic dysfunction at 16 wk, without hypertension. The SDT rat LV exhibited cardiomyocyte hypertrophy and increased hypoxia-inducible factor-1α expression at 8 wk and to a greater degree at 16 wk and interstitial fibrosis at 16 wk only. In SDT rats, coronary angiogenesis increased with enhanced capillary proliferation and upregulation of the angiogenic factor VEGF at 8 wk but decreased VEGF with enhanced capillary apoptosis and suppressed capillary proliferation despite the upregulation of VEGF at 16 wk. In SDT rats, the phosphorylation of VEGF receptor-2 increased at 8 wk alone, whereas the expression of the antiangiogenic factor thrombospondin-1 increased at 16 wk alone. All these events, except for hyperglycemia or blood pressure, were reversed by olmesartan medoxomil. These results suggest that LV ANG II in SDT rats at 8 and 16 wk induces cardiomyocyte hypertrophy without affecting hyperglycemia or blood pressure, which promotes and suppresses coronary angiogenesis, respectively, via VEGF and thrombospondin-1 produced from hypertrophied cardiomyocytes under chronic hypoxia. Thrombospondin-1 may play an important role in the progression of diabetic cardiomyopathy in this model.
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Affiliation(s)
- Takahiro Masuda
- Divisions of Nephrology, Department of Internal Medicine, Jichi Medical University, Yakushiji, Shimotsuke, Japan
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Abstract
Male Zucker diabetic fatty fa/fa (ZDF) rats develop obesity and insulin resistance at a young age, and then with aging, progressively develop hyperglycemia. This hyperglycemia is associated with impaired pancreatic β-cell function, loss of pancreatic β-cell mass, and decreased responsiveness of liver and extrahepatic tissues to the actions of insulin and glucose. Of particular interest are the insights provided by studies of these animals into the mechanism behind the progressive impairment of carbohydrate metabolism. This feature among others, including the development of obesity- and hyperglycemia-related complications, is common between male ZDF rats and humans with type 2 diabetes associated with obesity. We discuss the diabetic features and complications found in ZDF rats and why these animals are widely used as a genetic model for obese type 2 diabetes.
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Affiliation(s)
- Masakazu Shiota
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, USA.
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Hempe J, Elvert R, Schmidts HL, Kramer W, Herling AW. Appropriateness of the Zucker Diabetic Fatty rat as a model for diabetic microvascular late complications. Lab Anim 2012; 46:32-9. [DOI: 10.1258/la.2011.010165] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Male obese Zucker Diabetic Fatty (ZDF) rats develop type 2 diabetes around eight weeks of age, and are widely used as a model for human diabetes and its complications. The objective of the study was to test whether the complications manifested in the kidney and nerves of ZDF rats really correspond to human diabetic complications in their being related to the hyperglycaemic state. Four groups of ZDF rats were used. One lean (Fa/?) and one obese (fa/fa) untreated group served as non-diabetic and diabetic controls. In two further groups of obese (fa/fa) rats, diabetes was prevented by pioglitazone or delayed by food restriction. All rats were monitored up to 35 weeks of age with respect to their blood glucose, HbA1c and insulin levels, their kidney function (urinary glucose excretion, renal glucose filtration, glomerular filtration rate, albumin/creatinine ratio), and their nerve function (tactile and thermal sensory threshold and nerve conduction velocity). Pioglitazone prevented the development of diabetes, while food restriction delayed its onset for 8–10 weeks. Accordingly, kidney function parameters were similar to lean non-diabetic rats in pioglitazone-treated rats and significantly improved in food-restricted rats compared with obese controls. Kidney histology paralleled the functional results. By contrast, nerve functional evaluations did not mirror the differing blood glucose levels. We conclude that the ZDF rat is a good model for diabetic nephropathy, while alterations in nerve functions were not diabetes-related.
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Affiliation(s)
- J Hempe
- Diabetes Division, Translational Medicine, Sanofi-Aventis Deutschland GmbH, Industriepark Hoechst, H821, 65926 Frankfurt am Main, Germany
| | - R Elvert
- Diabetes Division, Translational Medicine, Sanofi-Aventis Deutschland GmbH, Industriepark Hoechst, H821, 65926 Frankfurt am Main, Germany
| | - H-L Schmidts
- Diabetes Division, Translational Medicine, Sanofi-Aventis Deutschland GmbH, Industriepark Hoechst, H821, 65926 Frankfurt am Main, Germany
| | - W Kramer
- Diabetes Division, Translational Medicine, Sanofi-Aventis Deutschland GmbH, Industriepark Hoechst, H821, 65926 Frankfurt am Main, Germany
| | - A W Herling
- Diabetes Division, Translational Medicine, Sanofi-Aventis Deutschland GmbH, Industriepark Hoechst, H821, 65926 Frankfurt am Main, Germany
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Conte D, Viscarra J, Nishiyama A, Ortiz RM. Chronic angiotensin receptor blockade suppresses intracardiac angiotensin II in angiotensin II-infused rats. Exp Biol Med (Maywood) 2011; 236:1449-53. [PMID: 22087022 DOI: 10.1258/ebm.2011.011159] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Accumulation of angiotensin II (Ang II) in tissues is an Ang II-receptor-mediated process. In pigs, acute angiotensin receptor blockade (ARB) reduced the heart-to-plasma ratio of Ang II following acute infusion. However in rats, chronic ARB treatment increased heart Ang II levels, suggesting that a differential response to ARB treatment may exist in the mammalian heart. Furthermore, the changes in heart aldosterone following chronic ARB treatment are not well described. To address the discrepancy in heart Ang II concentrations following ARB treatment, three groups (n = 6) of rats were chronically studied: (1) control; (2) angiotensin II (Ang II; 80 ng/min for 28 d); and (3) angiotensin II + olmesartan (ARB; 10 mg/kg/d for 21 d). Ang II-infusion increased intracardiac Ang II by 40% (53 ± 2 versus 74 ± 6 fmol/g) and intrarenal Ang II over 2-fold (96 ± 6 versus 207 ± 14 fmol/g), and chronic ARB treatment decreased Ang II by 48% in the heart (50 ± 7 fmol/g) and over two-fold in the kidney (92 ± 7 fmol/g), suggesting that accumulation of Ang II in the heart is receptor-mediated as in the kidney. Ang II increased plasma aldosterone 2.5-fold (1.4 ± 0.1 versus 3.5 ± 1.2 nmol/L) and was exacerbated by ARB treatment (5.6 ± 1.0 nmol/L). Intracardiac aldosterone was exacerbated by ARB treatment (control: 2.2 ± 0.3; Ang II: 2.7 ± 1.1; ARB: 7.8 ± 1.7 pmol/g). Suppression of intracardiac Ang II with ARB is consistent with the existing view of Ang II-receptor-mediated uptake by tissues.
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Affiliation(s)
- Debra Conte
- Division of Natural Sciences, University of California, Merced, CA 95343, USA
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Abstract
OBJECTIVE Angiotensin (ANG) II type 1 receptor (AT1R) blockers have neuroprotective effects against neuronal lesions. The present study examines whether the AT1R blocker olmesartan improves peripheral nerve dysfunction in rats with type 2 diabetes. METHODS Fourteen-week-old male type 2 diabetic Zucker diabetic fatty (ZDF) rats were orally administered with olmesartan (6 mg/kg per day; n = 7) or not treated (n = 7) and then followed up for nine weeks. Age-matched and sex-matched nondiabetic lean rats served as controls (n = 7). RESULTS Olmesartan for 9 weeks did not influence blood glucose and A1c levels that were higher in untreated ZDF (U-ZDF) rats than in control rats. In U-ZDF rats, myelinated fiber density and myelin areas of myelinated fibers in peroneal nerves significantly increased and decreased, respectively, and the intraepidermal nerve fiber density (IENFD) of footpad skin tended to decrease. The U-ZDF rats developed mechanical hyperalgesia, thermal hypoalgesia and slower sensory and motor nerve conduction in the sciatic-tibial nerves. Olmesartan increased myelin areas and IENFD and ameliorated sensory nerve conduction deficits. These beneficial effects of olmesartan were associated with ANG II and insulin receptor upregulation in sensory neurons as well as deactivation of Erk1/2 in sciatic nerves. CONCLUSION Olmesartan appears to improve the structure and function of small and large nerves and upregulate ANG II and insulin receptors in sensory neurons of rats with type 2 diabetes.
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Kang MJ, Kim HS, Jeon HS, Park JH, Lee BS, Ahn BK, Moon KY, Choi YW. In situ intestinal permeability and in vivo absorption characteristics of olmesartan medoxomil in self-microemulsifying drug delivery system. Drug Dev Ind Pharm 2011; 38:587-96. [PMID: 21988221 DOI: 10.3109/03639045.2011.619194] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
To characterize the intestinal absorption behavior of olmesartan medoxomil (OLM) and to evaluate the absorption-improving potential of a self-microemulsifying drug delivery system (SMEDDS), we performed in situ single-pass intestinal perfusion (SPIP) and in vivo pharmacokinetic studies in rats. The SPIP study revealed that OLM is absorbed throughout whole intestinal regions, favoring proximal segments, at drug levels of 10-90 μM. The greatest value for effective permeability coefficient (P(eff)) was 11.4 × 10(-6) cm/s in the duodenum (90 μM); the lowest value was 2.9 × 10(-6) cm/s in the ileum (10 μM). A SMEDDS formulation consisting of Capryol 90, Labrasol, and Transcutol, which has a droplet size of 200 nm and self-dispersion time of 21 s, doubled upper intestinal permeability of OLM. The SMEDDS also improved oral bioavailability of OLM in vivo: a 2.7-fold increase in the area under the curve (AUC) with elevated maximum plasma concentration (C(max)) and shortened peak time (T(max)) compared to an OLM suspension. A strong correlation (r(2) = 0.955) was also found between the in situ jejunal P(eff) and the in vivo AUC values. Our study illustrates that the SMEDDS formulation holds great potential as an alternative to increased oral absorption of OLM.
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Affiliation(s)
- Myung J Kang
- Division of Pharmaceutical Sciences, College of Pharmacy, Chung-Ang University, Dongjak-gu, Seoul, Korea
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Urushihara M, Kobori H. Angiotensinogen Expression Is Enhanced in the Progression of Glomerular Disease. ACTA ACUST UNITED AC 2011; 2:378-387. [PMID: 22247811 DOI: 10.4236/ijcm.2011.24064] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Intrarenal renin-angiotensin system (RAS) activation plays a critical role in the development and progression of renal injury. In the kidney, all of the RAS components are present and intrarenal angiotensin II (Ang II) is formed by multiple independent mechanisms. Angiotensinogen (AGT) is the only known substrate for renin that is a rate-limiting enzyme of the RAS. Recently, enhanced intrarenal AGT levels have been shown to reflect the intrarenal RAS status in hypertension, chronic glomerular disease and diabetic nephropathy. In this review, we focus on AGT expression of the diseased glomeruli in the progression of glomerular disease. An anti-glomerular basement membrane nephritis rat model developed progressive proteinuria and glomerular crescent formation, accompanied by increased macrophage infiltration and glomerular expression of AGT and Ang II. The addition of Ang II type 1 receptor blocker to CC-chemokine recaptor 2 antagonist markedly attenuated the induction of macrophage infiltration, AGT and Ang II, and reduced glomerular crescent formation. Next, the levels of glomerular AGT expression and marker of reactive oxygen species in Zucker diabetic fatty (ZDF) obese rats were higher than those in ZDF lean rats. Hydrogen peroxide (H(2)O(2)) induced an increase in the AGT expression in primary rat mesangial cells. Furthermore, the H(2)O(2)-induced upregulation of AGT was inhibited by a mitogen-activated protein kinase kinase and a c-Jun N-terminal kinase inhibitor. These data suggest the potential contribution of enhanced AGT expression in glomeruli to the intrarenal RAS activation for the development of glomerular disease.
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Affiliation(s)
- Maki Urushihara
- Department of Physiology, and Hypertension and Renal Center of Excellence Tulane University Health Sciences Center, New Orleans, USA
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22
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Adiponectin negatively correlated with carotid arterial structure in the leptin-resistant Zucker diabetic fatty rat. Artery Res 2011. [DOI: 10.1016/j.artres.2011.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Panchal SK, Brown L. Rodent models for metabolic syndrome research. J Biomed Biotechnol 2010; 2011:351982. [PMID: 21253582 PMCID: PMC3018657 DOI: 10.1155/2011/351982] [Citation(s) in RCA: 230] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2010] [Revised: 12/01/2010] [Accepted: 12/02/2010] [Indexed: 02/07/2023] Open
Abstract
Rodents are widely used to mimic human diseases to improve understanding of the causes and progression of disease symptoms and to test potential therapeutic interventions. Chronic diseases such as obesity, diabetes and hypertension, together known as the metabolic syndrome, are causing increasing morbidity and mortality. To control these diseases, research in rodent models that closely mimic the changes in humans is essential. This review will examine the adequacy of the many rodent models of metabolic syndrome to mimic the causes and progression of the disease in humans. The primary criterion will be whether a rodent model initiates all of the signs, especially obesity, diabetes, hypertension and dysfunction of the heart, blood vessels, liver and kidney, primarily by diet since these are the diet-induced signs in humans with metabolic syndrome. We conclude that the model that comes closest to fulfilling this criterion is the high carbohydrate, high fat-fed male rodent.
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Affiliation(s)
- Sunil K. Panchal
- Department of Biological and Physical Sciences, University of Southern Queensland, Toowoomba, QLD 4350, Australia
| | - Lindsay Brown
- Department of Biological and Physical Sciences, University of Southern Queensland, Toowoomba, QLD 4350, Australia
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Sengupta P, Sarkar AK, Bhaumik U, Chatterjee B, Roy B, Chakraborty US, Pal TK. Development and validation of an LC-ESI-MS/MS method for simultaneous quantitation of olmesartan and pioglitazone in rat plasma and its pharmacokinetic application. Biomed Chromatogr 2010; 24:1342-9. [DOI: 10.1002/bmc.1447] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Terashima H, Kato M, Yasumo H, Tsuchida H, Mizuno M, Sada T. A sensitive short-term evaluation of antifibrotic effects using newly established type I collagen reporter transgenic rats. Am J Physiol Renal Physiol 2010; 299:F792-801. [PMID: 20660018 DOI: 10.1152/ajprenal.00141.2009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Fibrosis is the final common pathway for various tissue lesions that lead to chronic progressive organ failure, and consequently effective antifibrotic drugs are strongly desired. However, there are few animal models in which it is possible to evaluate fibrosis sensitively in a short period of time. We therefore generated two transgenic rats harboring a firefly luciferase reporter gene under the control of the 5'-flanking region of rat α(1)(I) collagen (Col1a1-Luc Tg rats) and α(2)(I) collagen (Col1a2-Luc Tg rats). The luciferase activities of these transgenic rats were highly correlated with the hydroxyproline content in various organs. In unilateral ureteral obstruction (UUO), a well-characterized model of renal fibrosis, the luciferase activity in obstructed kidneys showed a significant increase after even 3 days of UUO, while the hydroxyproline content showed little increase. In addition, the renal hydroxyproline content had a higher correlation with the luciferase activity than α(1)(I) collagen mRNA level for over 2 wk after UUO. Although both an ANG II type 1 receptor blocker (ARB), olmesartan, and a transforming growth factor-β (TGF-β) type I receptor kinase (ALK5) inhibitor, SB-431542, inhibited renal luciferase activities in UUO, only SB-431542 inhibited luciferase activity induced by TGF-β1 in isolated glomeruli. Double immunostaining for luciferase and α-smooth muscle actin (α-SMA) revealed that some α-SMA-positive tubular epithelial cells and tubular interstitial cells produced type I collagen, which would lead to renal fibrosis. Thus collagen reporter transgenic rats would be very useful for the evaluation of antifibrotic effects and analysis of their mechanisms.
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Affiliation(s)
- Hideki Terashima
- Biological Research Laboratories I, R&D Division, Daiichi Sankyo Co., Ltd., 1-2-58, Hiromachi, Shinagawa-ku, Tokyo 140-8710, Japan
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Çaǧlar S, Önal A. Two simple and rapid spectrophotometric methods for the determination of a new antihypertensive drug olmesartan in tablets. JOURNAL OF ANALYTICAL CHEMISTRY 2010. [DOI: 10.1134/s1061934810030056] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Abstract
PURPOSE Diabetes mellitus is a group of debilitating and costly diseases with multiple serious complications. Lower urinary tract complications or diabetic uropathy are among the most common complications of diabetes mellitus, surpassing widely recognized complications such as neuropathy and nephropathy. Diabetic uropathy develops in individuals with types 1 and 2 diabetes, and little is known about the natural history of these common and troublesome complications. Animal models have the potential to reveal mechanisms and aid in the development of treatment strategies. MATERIALS AND METHODS We present a review of available animal models of diabetes mellitus relative to their use in the study of diabetic uropathy. RESULTS Large and small animal models of diabetes mellitus are available. While large animals such as dogs and swine may closely mirror the human disease in size and phenotype, the time between diabetic complication onset and development, and associated husbandry expenditures can make acquiring data on statistically valid sample sizes prohibitively expensive. In contrast, small animal models (rats and mice) have much lower expenditures for a larger number of animals and compressed observation time due to a shorter life span. Also, mice are readily manipulated genetically to facilitate the isolation of the effect of single genes (transgenic and knockout mice). Type 1 diabetes mellitus can be induced chemically with streptozotocin, which is selectively toxic to pancreatic beta cells. Type 2 diabetes mellitus models have been developed by selective breeding for hyperglycemia with or without associated obesity. Diabetic uropathy has been noted in several well characterized, predictable animal models of diabetes mellitus. CONCLUSIONS Diabetic uropathy, including diabetic bladder dysfunction, has been more frequently studied in small animals with type I diabetes. The recent availability of transgenic models provides a new opportunity for further studies of diabetic uropathy in mouse models of types I and II diabetes mellitus.
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Affiliation(s)
- Firouz Daneshgari
- Department of Urology and Female Pelvic Surgery, State University of New York, Upstate Medical University, Syracuse, New York, USA.
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Albayrak S, Ordu S, Ozhan H, Yazici M, Aydin M, Alemdar R, Kaya A. Effect of olmesartan medoxomil on cystatin C level, left ventricular hypertrophy and diastolic function. Blood Press 2009; 18:187-91. [DOI: 10.1080/08037050903047236] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Cosson E, Valensi P, Laude D, Mesangeau D, Dabire H. Arterial stiffness and the autonomic nervous system during the development of Zucker diabetic fatty rats. DIABETES & METABOLISM 2009; 35:364-70. [PMID: 19648048 DOI: 10.1016/j.diabet.2009.02.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2008] [Revised: 02/23/2009] [Accepted: 02/24/2009] [Indexed: 11/25/2022]
Abstract
AIM This study aimed to investigate the role played by sympathovagal balance in arterial stiffness, a common feature of insulin resistance and type 2 diabetes. METHODS We investigated the relationship between autonomic nervous system activity and arterial stiffness in Zucker diabetic fatty rats (ZDF: Gmi-fa/fa) and their age-matched controls (lean: ?/fa). Using simultaneous catheterization of the proximal and distal aorta, we measured intra-arterial blood pressure (BP), heart rate (HR), their variability (spectral analysis) and aortic pulse wave velocity (PWV) in a series of at least six conscious rats aged 6, 12, 18 and 24 weeks. RESULTS BP and PWV increased with age (P<0.001) in both strains with no differences between strains, despite the insulin resistance already present at 6 weeks in ZDF rats. HR was significantly lower (P<0.001) in ZDF than in lean rats. In ZDF compared with lean rats, the low-frequency (LF) component of the systolic BP variations and the LF/high-frequency (HF) component of the pulse interval (PI) variation ratio were reduced (P<0.01 and P<0.05, respectively), while the HF component of the PI (HF-PI) variation was raised (P<0.05). PWV was negatively correlated with HF-PI (r=-0.37, P<0.01), but not with biochemical parameters. HF-PI was an independent variable explaining the variation in PWV. CONCLUSION During the development of disease of ZDF rats, sympathovagal balance might account for the lack of increase in PWV.
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Affiliation(s)
- E Cosson
- Inserm, EMI-U0107, Paris, France.
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Punzi HA. Efficacy and safety of olmesartan medoxomil alone and in combination with hydrochlorothiazide. Expert Rev Cardiovasc Ther 2009; 7:229-239. [DOI: 10.1586/14779072.7.3.229] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
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Huang CQ, Ma GZ, Tao MD, Ma XL, Liu QX, Feng J. The relationship among renal injury, changed activity of renal 1-alpha hydroxylase and bone loss in elderly rats with insulin resistance or Type 2 diabetes mellitus. J Endocrinol Invest 2009; 32:196-201. [PMID: 19542734 DOI: 10.1007/bf03346452] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
BACKGROUND AND OBJECTIVE Chronic kidney disease can lead to a decrease in active vitamin D [1,25-(OH)2D], which may be reversed by 1-alpha hydroxyvitamin D [1-alpha(OH)D]. Renal 1-alpha hydroxylase, expressed in renal tubular epithelial cells, is a key enzyme in the synthesis of 1,25-(OH)2D. 1,25- (OH)2D plays an important role in the regulation of calcium and phosphate metabolism, and its deficiency can result in osteoporosis. Type 2 diabetes mellitus (T2DM) and insulin resistance (IR) are associated with renal injury, decrease in 1,25-(OH)2D and bone loss. The study aimed to explore the relationship among renal injury, decrease in 1,25-(OH)2D and bone loss in the presence of IR or T2DM, as well as the role of renal 1-alpha hydroxylase in the process. MATERIALS AND METHODS Fifty 18-month-old male Wistar rats were randomized into 5 groups: normal control group (Group N), IR group (Group I), T2DM group (Group D), No.1 treatment group (Group T1), and No.2 treatment group (Group T2), 10 in each group. High-fat diet was administered to induce IR, while high-fat diet and low-dose streptozotocin were jointly applied to induce T2DM. Rats in Groups T1 and T2 were treated with vitamin D and 1-alpha(OH)D, respectively. At week 12, IR was determined by the use of euglycemic insulin clamp technique for rats in each group, and then glucose infusion rate (GIR) was calculated. Meanwhile, urinary albumin (UA), serum 25-(OH)D and 1,25-(OH)2D levels were determined by radioimmunoassay. After the rats were sacrificed, bone mineral density (BMD) in femoral bone and lumbar vertebrae was measured by the use of dual energy X-ray absorption. RESULTS The GIR in Group N was significantly higher than that of the other 4 groups (p<0.01). Compared with Groups N (p<0.01) or I (p<0.05), the UA levels in Groups D, T1, and T2 were obviously higher. The UA level in Group I was higher than that of Group N, but the difference was not significant (p>0.05). In Groups D and I, the UA levels showed a negative correlation with GIR. No significant difference was observed in the levels of 25-hydroxyvitamin D [25-(OH)D]. The levels of 1,25-(OH)2D in Groups D and T1 were markedly lower than that of Groups N or T2 (p<0.01). The 1,25-(OH)2D level in Group I was lower than that of Group N (p<0.05), but higher than that of Group D (p<0.01). The 1,25-(OH)2D level in Group T2 was nearly equivalent to that of Group N. In Groups D and I, the levels of 1,25-(OH)2D were negatively correlated with UA, and positively correlated with GIR. The BMD levels in lumbar vertebrae or femoral bone in Groups D and T1 were similar, but both were lower than that of Groups T2 (p<0.05) and N (p<0.01). The BMD levels were lower in Groups I and T2 compared with that of Group N (p<0.05), but higher than that of Groups D and T1 (p<0.05). The BMD levels in lumbar vertebrae or femoral bone in Groups I and D were positively correlated with GIR. The BMD level in lumbar vertebrae or femoral bone in Group D showed negative correlation with UA. CONCLUSION In elderly rats with T2DM or IR, renal injury may cause decreased activity of renal 1-alpha hydroxylase, which may result in bone loss and disturbance in VD metabolism, mainly manifesting as a significant reduction in the 1,25-(OH)2D level.
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MESH Headings
- 25-Hydroxyvitamin D3 1-alpha-Hydroxylase/metabolism
- Aging/metabolism
- Aging/physiology
- Animals
- Blood Glucose/metabolism
- Bone Density/physiology
- Calcifediol/blood
- Calcitriol/blood
- Diabetes Mellitus, Experimental/blood
- Diabetes Mellitus, Experimental/complications
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Type 2/blood
- Diabetes Mellitus, Type 2/complications
- Diabetes Mellitus, Type 2/metabolism
- Insulin Resistance/physiology
- Kidney/enzymology
- Male
- Osteoporosis/blood
- Osteoporosis/etiology
- Osteoporosis/metabolism
- Rats
- Rats, Wistar
- Renal Insufficiency, Chronic/blood
- Renal Insufficiency, Chronic/complications
- Renal Insufficiency, Chronic/metabolism
- Streptozocin
- Vitamin D Deficiency/etiology
- Vitamin D Deficiency/metabolism
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Affiliation(s)
- C-Q Huang
- Department of Geriatrics, The Third Hospital of Mianyang, Mianyang, PR China.
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Ikeda H, Hamamoto Y, Honjo S, Nabe K, Wada Y, Koshiyama H. Olmesartan reduced microalbuminuria in Japanese subjects with type 2 diabetes. Diabetes Res Clin Pract 2009; 83:117-8. [PMID: 19062123 DOI: 10.1016/j.diabres.2008.10.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/31/2007] [Indexed: 11/21/2022]
Abstract
We investigated the effect of olmesartan on early diabetic nephropathy in hypertensive patients with type 2 diabetes by its replacement of other angiotensin II type 1 receptor blockers (ARBs) by olmesartan. The urinary albumin/creatinine ratio significantly decreased. The present result suggests a possibility that olmesartan may have more effect on early nephropathy than other ARBs.
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Affiliation(s)
- Hiroki Ikeda
- Center for Diabetes & Endocrinology, The Tazuke Kofukai Foundation Medical Research Institute Kitano Hospital, Osaka, Japan
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Soler MJ, Ye M, Wysocki J, William J, Lloveras J, Batlle D. Localization of ACE2 in the renal vasculature: amplification by angiotensin II type 1 receptor blockade using telmisartan. Am J Physiol Renal Physiol 2008; 296:F398-405. [PMID: 19004932 DOI: 10.1152/ajprenal.90488.2008] [Citation(s) in RCA: 175] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Angiotensin-converting enzyme (ACE)2 is a carboxypeptidase that degrades angiotensin II and other peptides. In the kidney, ACE2 localization within the glomerulus and tubules is cell specific. This study was aimed to investigate the localization of ACE2 within the renal vasculature. We also studied the effect of the administration of a specific angiotensin II type 1 receptor blocker, telmisartan, on ACE2 expression in the renal vasculature. ACE2 and ACE were localized in renal arterioles using confocal microscopy and specific cell markers. Quantitative measurements of ACE2 and ACE mRNA were estimated in kidney arterioles isolated by laser capture microdissection using real-time PCR. In kidney arterioles, ACE was localized in the endothelial layer, whereas ACE2 was localized in the tunica media. In mice treated with telmisartan (2 mg.kg(-1).day(-1)) for 2 wk, ACE2 expression was increased by immunostaining, whereas ACE expression was decreased. This was reflected in a decrease in the ACE/ACE2 ratio compared with vehicle-treated controls (0.53 +/- 0.14 vs. 7.59 +/- 2.72, P = 0.027, respectively). In kidney arterioles isolated by laser capture microdissection, the ACE/ACE2 mRNA ratio was also decreased compared with control mice (1.21 +/- 0.31 vs. 4.63 +/- 0.86, P = 0.044, respectively). In conclusion, in kidney arterioles ACE2 is preferentially localized in the tunica media, and its expression is increased after administration of the angiotensin II type 1 receptor blocker, telmisartan. Amplification of ACE2 in the renal vasculature may contribute to the therapeutic action of telmisartan by increasing angiotensin II degradation.
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Affiliation(s)
- María José Soler
- Department of Medicine, Division of Nephrology and Hypertension, The Feinberg School of Medicine, Northwestern Univ., 320 E Superior, Chicago, IL 60611, USA
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Li Y, Qi Y, Kim MS, Xu KZY, Huang THW, Rong X, Murray M, Yamahara J. Increased renal collagen cross-linking and lipid accumulation in nephropathy of Zucker diabetic fatty rats. Diabetes Metab Res Rev 2008; 24:498-506. [PMID: 18613221 DOI: 10.1002/dmrr.874] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND Zucker diabetic fatty (ZDF) rat is a genetic model of type 2 diabetes and obesity. The mechanism underlying nephropathy in ZDF rats, however, remains unclear. METHODS ZDF rats were compared to age-matched Zucker lean (ZL) rats. Physiological and blood biochemical parameters, renal glomerular cross-sectional area (hematoxylin-eosin staining), fibrosis (van Giesen staining), collagen composition (Sircol Collagen Assay), lipids (enzymatic method) and mRNA expression (RT-PCR) were determined. RESULTS ZDF rats showed an increase in renal-insoluble collagen content and the ratio of renal-insoluble to salt-soluble collagen (2- and 1.5-fold of the control animals). There were increases in renal glomerulosclerosis and interstitial fibrosis in ZDF rats (increased to 2-fold) in the glomerular mesangium and tubulointerstitium, and increased glomerular area. Renal triglyceride accumulated to greater than 2-fold of those levels in ZL rats. These changes were accompanied by hypoalbuminemia, and elevated plasma blood urea nitrogen and uric acid levels. Gene profiling showed increased expression of transcripts encoding the glomerulosclerotic mediator collagens I and IV, plasminogen activator inhibitor-1, transforming growth factor-beta1, and angiotensin II type 1 receptor in ZDF rat kidney. Moreover, renal expression of mRNAs encoding sterol regulatory element-binding protein-1, a nuclear transcription factor that activates genes involved in fatty acid synthesis, and acetyl-CoA carboxylase, a key enzyme that mediates fatty acid synthesis, was increased in ZDF rats. CONCLUSIONS Our findings suggest that dysregulated gene expression may result in increased renal collagen cross-linking and lipid accumulation, that may be associated with development of nephropathy in the animal model of type 2 diabetes and obesity.
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Affiliation(s)
- Yuhao Li
- Faculty of Pharmacy, The University of Sydney, NSW, Australia.
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Yi SS, Hwang IK, Chun MS, Kim YN, Kim IY, Lee IS, Seong JK, Yoon YS. Glucocorticoid receptor changes associate with age in the paraventricular nucleus of type II diabetic rat model. Neurochem Res 2008; 34:851-8. [PMID: 18758953 DOI: 10.1007/s11064-008-9836-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2008] [Accepted: 08/12/2008] [Indexed: 12/25/2022]
Abstract
Diabetes is a metabolic disorder that is associated with the dysregulation of a number of systems within the body. In the present study, we investigated glucocorticoid receptor (GR) immunoreactivity and its protein levels in the paraventricular nuclei of 4-, 12-, 20- and 30-week-old Zucker diabetic fatty (fa/fa, ZDF) and in Zucker lean control (fa/+ or +/+, ZLC) rats, because the progressive induction of diabetes is detectable in this model after 7 weeks of age and chronic diabetic conditions are maintained after 12 weeks of age. GR immunoreactivity was detected in parvocellular paraventricular nuclei and this and GR protein levels were exponentially increased according to the ages. In particular, GR immunoreactivities and protein levels were markedly more increased in 30-week-old ZDF rats than in age-matched ZLC group and in younger ZDF group. The present study suggests that GR immunoreactivity and its protein level is associated with a degenerative phenotype in the hypothalamus of from 12-weeks old in the ZDF rat type II diabetes model.
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Affiliation(s)
- Sun Shin Yi
- Department of Anatomy and Cell Biology, College of Veterinary Medicine and BK21 Program for Veterinary Science, Seoul National University, Seoul, South Korea
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Namikoshi T, Tomita N, Satoh M, Haruna Y, Kobayashi S, Komai N, Sasaki T, Kashihara N. Pioglitazone enhances the antihypertensive and renoprotective effects of candesartan in Zucker obese rats fed a high-protein diet. Hypertens Res 2008; 31:745-55. [PMID: 18633187 DOI: 10.1291/hypres.31.745] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The metabolic syndrome is a risk factor for the development of chronic kidney disease. Angiotensin II type 1 receptor blockers (ARBs) and thiazolidinediones (TZDs) provide renovascular protection, probably in the metabolic syndrome. However, the effect of both agents administered together in patients with metabolic syndrome remains to be determined. The aim of this study was to assess the effects of ARB plus TZD combination therapy in Zucker obese rats fed a high-protein diet, an animal model of metabolic syndrome and renal injury. Zucker obese rats were fed a high-protein diet (OHP; n=6), a high-protein diet containing candesartan, an ARB (OHP+C; n=6), or a high-protein diet containing both candesartan and pioglitazone (OHP+CP; n=6) for 12 weeks. Systolic blood pressure and urinary protein excretion were measured throughout the study, and renal histology and immunohistochemistry were assessed at 12 weeks. OHP rats developed hypertension (157+/-4 mmHg) and proteinuria (178+/-44 mg/d), and these conditions were significantly ameliorated by candesartan (to 143+/-3 mmHg and 84+/-25 mg/d, respectively). Pioglitazone enhanced the antihypertensive and anti-proteinuric effects of candesartan (121+/-3 mmHg, 16+/-8 mg/d, respectively). Histologically, candesartan ameliorated glomerulosclerosis, podocyte injury, interstitial fibrosis and monocyte/macrophage infiltration into the tubulointerstitium in the kidneys of OHP rats. Pioglitazone abrogated residual interstitial fibrosis in the kidneys of OHP+C rats. Our results suggested that pioglitazone augmented the antihypertensive, anti-proteinuric and possibly renal anti-fibrotic actions of candesartan in Zucker obese rats fed a high-protein diet. The combination therapy of ARB and TZD may protect against renal injury in patients with metabolic syndrome.
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Affiliation(s)
- Tamehachi Namikoshi
- Division of Nephrology, Department of Internal Medicine, Kawasaki Medical School, Kurashiki, Japan
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Figarola JL, Loera S, Weng Y, Shanmugam N, Natarajan R, Rahbar S. LR-90 prevents dyslipidaemia and diabetic nephropathy in the Zucker diabetic fatty rat. Diabetologia 2008; 51:882-91. [PMID: 18317729 DOI: 10.1007/s00125-008-0935-x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2007] [Accepted: 01/08/2008] [Indexed: 11/24/2022]
Abstract
AIMS/HYPOTHESIS Previous studies have shown that LR-90, a new inhibitor of AGE formation, prevented the development of experimental type 1 diabetic nephropathy. In this study, we examined the effects of LR-90 in the Zucker diabetic fatty (ZDF) rat, a model of type 2 diabetes and metabolic syndrome, and investigated the mechanisms by which it may protect against renal injury. METHODS Male ZDF rats were treated without or with LR-90 from age 13 to 40 weeks. Metabolic and kidney functions and renal histology were evaluated. AGE accumulation and the production of the receptor for AGE (AGER) were measured. Profibrotic growth factors, extracellular matrix proteins and intracellular signalling pathways associated with glomerular and tubular damage were also analysed. RESULTS LR-90 dramatically reduced plasma lipids in ZDF rats, with only modest effects on hyperglycaemia. Renal AGE, AGER and lipid peroxidation were all attenuated by LR-90. LR-90 significantly retarded the increase in albuminuria and proteinuria. This was associated with reduction in glomerulosclerosis and tubulointerstitial fibrosis, concomitant with marked inhibition of renal overproduction of TGF-beta1, connective tissue growth factor, fibronectin and collagen IV. Additionally, LR-90 downregulated the activation of key mitogen-activated protein kinases (MAPKs) and nuclear factor kappa B (NF-kappaB) in the renal cortex. CONCLUSIONS/INTERPRETATION These results support our earlier studies on the renoprotective effects of LR-90 on type 1 diabetic nephropathy and provide further evidence that LR-90, an AGE inhibitor with pleiotrophic effects, may also be beneficial for the prevention of type 2 diabetic nephropathy, where multiple risk factors, such as hyperglycaemia, dyslipidaemia, obesity, insulin resistance and hypertension, contribute to renal injury.
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Affiliation(s)
- J L Figarola
- Department of Diabetes, Endocrinology and Metabolism, Gonda Building, City of Hope National Medical Center, 1500 E. Duarte Road, Duarte, CA 91010, USA
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Miyata K, Ohashi N, Suzaki Y, Katsurada A, Kobori H. Sequential activation of the reactive oxygen species/angiotensinogen/renin-angiotensin system axis in renal injury of type 2 diabetic rats. Clin Exp Pharmacol Physiol 2008; 35:922-7. [PMID: 18430060 DOI: 10.1111/j.1440-1681.2008.04938.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
1. The present study was performed to test the hypothesis that the reactive oxygen species (ROS)-angiotensinogen (AGT)-renin angiotensin system (RAS) axis is sequentially activated in the development of diabetic nephropathy in Zucker diabetic fatty (ZDF) obese rats. 2. Genetic pairs of male ZDF obese and control ZDF lean rats (n = 12 of each species) were killed every 3 weeks from 12 to 21 weeks of age (n = 6 at each time point). 3. The ZDF obese rats developed diabetes mellitus at 12 weeks. At that time, urinary excretion rates of 8-isoprostane were similar between the groups; however, urinary 8-isoprostane levels were significantly increased at 15 weeks in ZDF obese rats compared with controls (36 +/- 6 vs 15 +/- 2 ng/day, respectively). At 15 weeks, protein levels of cortical angiotensinogen were similar between groups; however, cortical angiotensinogen levels were significantly increased at 18 weeks in ZDF obese rats compared with controls (relative ratio of 2.32 +/- 0.21 vs 1.00 +/- 0.20, respectively). At 12 weeks, angiotensin (Ang) II-like immunoreactivity was similar between groups in both the glomeruli and tubules; however, AngII-like immunoreactivity was increased significantly at 21 weeks in ZDF obese rats compared with controls (relative ratios of 1.98 +/- 0.55 vs 1.00 +/- 0.03, respectively, for glomeruli and 1.58 +/- 0.16 vs 1.00 +/- 0.13, respectively, for tubules). Moreover, at 21 weeks, the desmin-positive area in the glomeruli (0.63 +/- 0.08 vs 0.22 +/- 0.05%) and Masson's trichrome stain-positive area in the interstitium (4.97 +/- 0.05 vs 3.18 +/- 0.41%) were significantly increased in ZDF obese rats compared with controls, even though these differences had not been observed earlier. 4. These data suggest that the sequential activation of the ROS-AGT-RAS axis plays an important role in the development of diabetic nephropathy in ZDF obese rats.
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Affiliation(s)
- Kayoko Miyata
- Department of Medicine, and Hypertension and Renal Center of Excellence, Tulane University Health Sciences Center, New Orleans, Louisiana, USA
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Glomerular renin angiotensin system in streptozotocin diabetic and Zucker diabetic fatty rats. Transl Res 2008; 151:208-16. [PMID: 18355768 DOI: 10.1016/j.trsl.2008.01.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2007] [Revised: 01/04/2008] [Accepted: 01/08/2008] [Indexed: 11/21/2022]
Abstract
Substantial evidence suggests that the intrarenal renin-angiotensin system (RAS) plays a role in the pathogenesis of diabetic nephropathy. Although the glomerular RAS is activated in the streptozotocin (STZ)-diabetic rat, the status of the glomerular RAS in the Zucker diabetic fatty (ZDF) rat, which is a commonly used genetic model of diabetes, is not known. Angiotensinogen (AGT), angiotensin II (Ang II), angiotensin converting enzyme (ACE), and angiotensin converting enzyme 2 (ACE2) were measured in glomeruli isolated from 4-week-old STZ-diabetic rats and 32-week-old ZDF rats. Glomerular injury was evaluated by histopathologic methods. Both STZ-diabetic and ZDF rats exhibited marked hyperglycemia and renal hypertrophy, but only ZDF rats demonstrated proteinuria and glomerulosclerosis. Glomerular AGT and Ang II levels were increased significantly in STZ-diabetic compared with nondiabetic control rats, accompanied by a reduction in ACE2 activity. In contrast, glomerular AGT, Ang II, and ACE2 were similar in ZDF rats and lean controls. ACE levels were not affected by diabetes in either diabetic model. In conclusion, the glomerular RAS is activated in the STZ diabetic rat but not in the ZDF rat despite a similar degree of hyperglycemia. The mechanism of nephropathy in the ZDF rat may involve factors other than hyperglycemia and RAS activation, such as hypertension and hyperlipidemia.
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Hwang IK, Yi SS, Kim YN, Kim IY, Lee IS, Yoon YS, Seong JK. Reduced hippocampal cell differentiation in the subgranular zone of the dentate gyrus in a rat model of type II diabetes. Neurochem Res 2007; 33:394-400. [PMID: 17712629 DOI: 10.1007/s11064-007-9440-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2007] [Accepted: 07/09/2007] [Indexed: 11/30/2022]
Abstract
It has recently been reported that diabetes mellitus is strongly associated with neurodegenerative and functional disorders of the central nervous system. In the present study, we investigated the changes in proliferating neurons in the dentate gyrus of type II diabetic rats using doublecortin (DCX), a marker of progenitors differentiating into neurons. At 4 weeks after birth, there were no differences in the blood glucose levels of Zucker diabetic fatty (ZDF) rats or Zucker lean control (ZLC) rats. DCX-immunoreactive neurons were detectable in the subgranular zone of the dentate gyrus in both the ZDF and ZLC rats; however, DCX immunoreactivity was higher in the ZLC rats than in the ZDF rats. At 12 weeks after birth, the blood glucose level was significantly increased by 400 mg/dl in the ZDF rats, but the blood glucose level in the ZLC rats was only slightly increased by 152.3 mg/dl. DCX immunoreactivity was significantly decreased in 12-week-old rats in comparison to 4-week-old rats. Some DCX-immunoreactive neurons were detectable in the subgranular zone of the dentate gyrus in the ZLC rats. However, only a few DCX-immunoreactive neurons were observed in the ZDF rats, and the DCX-immunoreactive neurons in the ZDF rats did not show fully developed processes. These results suggest that DCX-immunoreactive neurons were significantly decreased in an age-dependent manner and that DCX-immunoreactive neurons were also reduced in diabetic rats. In addition, the reduction in DCX-immunoreactive neurons in age matched rats may be associated with type II diabetes.
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Affiliation(s)
- In Koo Hwang
- Department of Anatomy and Cell Biology, College of Veterinary Medicine and BK21 Program for Veterinary Science, Seoul National University, Seoul 151-742, South Korea
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Chrysant SG, Dimas B, Shiraz M. Treatment of hypertension with olmesartan medoxomil, alone and in combination with a diuretic: an update. J Hum Hypertens 2007; 21:699-708. [PMID: 17554345 DOI: 10.1038/sj.jhh.1002241] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Olmesartan medoxomil is an angiotensin II (Ang II) receptor blocker (ARB) that has been approved by the US Food and Drug Administration (FDA) for the treatment of hypertension. It is a prodrug that is hydrolysed in the gut into its active metabolite, olmesartan (RNH-6270). Olmesartan is highly selective for the Ang II type 1 receptor (AT1) to which it binds completely and insurmountably and has very little affinity for the other receptor subtypes AT2 and AT4. After oral administration, in animals and humans, it achieves a maximal blood drug concentration within a maximal time of approximately 2 h. It is then slowly eliminated in the urine and faeces. His half-life is approximately 13 h, which makes it suitable for once-daily administration. Olmesartan medoxomil given orally in single daily doses of 20-40 mg has demonstrated significant blood pressure (BP) lowering effects in hypertensive patients. A medline search for the preparation of this manuscript was conducted and revealed 128 references, from 2000 to 2007. Of these, only 16 well-designed prospective clinical trials were selected. The remaining were either animal studies, reviews or studies in progress. In well-designed clinical trials, olmesartan medoxomil has demonstrated similar antihypertensive actions to the other antihypertensive drugs, as well as other members of its class given the highest recommended doses. In addition, the BP lowering effect of olmesartan, like the other members of its class, is greatly enhanced in combination with a diuretic. Its safety profile is similar to the other ARBs and no different than placebo.
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Affiliation(s)
- S G Chrysant
- Oklahoma Cardiovascular and Hypertension Center, University of Oklahoma School of Medicine, Oklahoma City, OK, USA.
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Kadowaki D, Anraku M, Tasaki Y, Kitamura K, Wakamatsu S, Tomita K, Gebicki JM, Maruyama T, Otagiri M. Effect of Olmesartan on Oxidative Stress in Hemodialysis Patients. Hypertens Res 2007; 30:395-402. [PMID: 17587751 DOI: 10.1291/hypres.30.395] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The effect of olmesartan, an inverse angiotensin II type 1 receptor blocker (ARB), on oxidative stress in hemodialysis (HD) patients is not fully understood, and has not been widely investigated in vitro or in vivo. We determined the amount of oxidized albumin and albumin hydroperoxides formed during incubation in the absence and presence of olmesartan by high-performance liquid chromatography (HPLC) and by a ferrous oxidation xylenol assay in an in vitro study. Six hypertensive HD patients were treated with 40 mg of olmesartan once daily, and blood pressure monitoring (BPM) was performed after 0, 4, and 8 weeks of treatment. The ratio of oxidized to unoxidized albumin was also determined. The oxidized albumin ratios and levels of albumin hydroperoxides were significantly decreased in a concentration-dependent manner in the presence of olmesartan, compared with the absence of olmesartan (p<0.05) in in vitro studies. In HD patients, olmesartan also significantly reduced systolic and diastolic blood pressure after 4 weeks, with a further significant decrease after 8 weeks. The ratio of oxidized to unoxidized albumin was markedly decreased after 4 weeks and these lower levels were maintained at 8 weeks. Olmesartan effectively lowered the extent of oxidation of albumin in both in vitro and in vivo studies, and this effect might confer benefits beyond a reduction in blood pressure.
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Affiliation(s)
- Daisuke Kadowaki
- Department of Biopharmaceutics, Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto, Japan
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Mizuno M, Sada T, Kato M, Fukushima Y, Terashima H, Koike H. The effect of angiotensin II receptor blockade on an end-stage renal failure model of type 2 diabetes. J Cardiovasc Pharmacol 2006; 48:135-42. [PMID: 17086090 DOI: 10.1097/01.fjc.0000245241.79959.d6] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The effect of olmesartan medoxomil (OLM), an angiotensin II receptor blocker (ARB), on advanced nephropathy and mortality was evaluated in Zucker Diabetic Fatty (ZDF) rats, a type 2 diabetes model. OLM was administered from 36 weeks of age, when the animals developed advanced proteinuria. OLM effectively suppressed the progression of proteinuria. The ZDF rats started to die at 50 weeks of age, which was accompanied by abrupt increase in blood urea nitrogen, suggesting that the cause of death was renal insufficiency. OLM suppressed increases in blood urea nitrogen and increased the survival rate of the ZDF rats. The histological examination revealed that the renal damage was ameliorated by OLM. The macrophage infiltration and monocyte chemoattractant protein-1 (MCP-1) expression was increased in the glomeruli and tubulointerstitium of the ZDF rat kidneys, and the increase was lessened by OLM. In a separate study, albumin increased MCP-1 release from cultured tubular epithelial cells. These results suggest that protein leakage from the glomeruli stimulates MCP-1 production in tubular cells and that MCP-1 released into the interstitial space induces macrophage infiltration and inflammation. It is conceivable that the beneficial actions of ARB on diabetic nephropathy are, at least in part, due to decrease of proteinuria and the subsequent reduction of inflammatory changes in tubular cells.
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Affiliation(s)
- Makoto Mizuno
- Pharmacodymanics Research Laboratories, the Pharmacology and Molecular Biology Research Laboratories, and R&D Headquarters, Sankyo Co. Ltd., Tokyo, Japan
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Suzaki Y, Ozawa Y, Kobori H. Intrarenal oxidative stress and augmented angiotensinogen are precedent to renal injury in Zucker diabetic fatty rats. Int J Biol Sci 2006; 3:40-6. [PMID: 17200690 PMCID: PMC1657083 DOI: 10.7150/ijbs.3.40] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2006] [Accepted: 10/27/2006] [Indexed: 12/31/2022] Open
Abstract
The Zucker diabetic fatty (ZDF) rat is a model of type II diabetes and metabolic syndrome based on impaired glucose tolerance caused by the inherited insulin-resistance gene. The ZDF rat exhibits progressive nephropathy; however, the detailed mechanisms have remained unclear. This study was performed to examine the possible involvement of enhanced intrarenal angiotensinogen in the development of renal injury in ZDF rats. Genetic pairs of male ZDF rats and control lean rats (N=6 each) were maintained from 12 to 17 weeks of age. At 17 weeks of age, fasting blood glucose and urinary 8-isoprostane levels were significantly higher in ZDF rats compared with the controls. Systolic blood pressure progressively increased in ZDF rats from 120+/-1 to 137+/-1 mmHg during this period. In contrast, systolic blood pressure did not increase in the controls. Kidney angiotensinogen protein levels were significantly increased in ZDF rats compared with the controls (1.83+/-0.34 vs. 1.00+/-0.17, relative ratio). Expression of angiotensin II type 1a receptor mRNA was similar between these groups. The measured indices of renal damage in the present study (glomerular sclerosis, interstitial expansion, glomerular macrophage infiltration, and renal arterial proliferation) were not significantly increased at this stage in ZDF rats. However, we previously showed that the increased reactive oxygen species-related angiotensinogen enhancement plays an important role in the development of renal injury in a genetic salt-sensitive hypertension. Thus, the present data suggest that elevated reactive oxygen species and reactive oxygen species-associated augmentation of intrarenal angiotensinogen may initiate the development of renal injury in ZDF rats.
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Affiliation(s)
- Yuki Suzaki
- Department of Physiology, and Hypertension and Renal Center of Excellence, Tulane University Health Sciences Center, New Orleans, LA 70112-2699, USA
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Abstract
The incidence of type-2 diabetes is increasing throughout the world. By 2010, 350 million people will have this disease. Microalbuminuria is present in more than one third, for some at diabetes diagnosis. Rather than a complication, it is an indication of a vascular disorder that is part of the metabolic syndrome. 25% will develop end-stage kidney failure. Several studies have identified microalbuminuria or proteinuria as an independent cardiovascular risk factor. Others have shown that antihypertensive treatments acting on the renin-angiotensin system (ACE inhibitors, ARBs agents) can reduce the progression of nephropathy in people with hypertension, type 2 diabetes and microalbuminuria. The "nephroprotective" effects of these drug classes, beyond their role in blood-pressure reduction, are suggested by modifications in renal structure and protein expression. But no study has so far examined their value in primary prevention in persons with type 2 diabetes without--but at risk of developing--microalbuminuria. The Roadmap study (Randomized Olmesartan And Diabetes Microalbuminuria Prevention Study) of primary prevention has as its objective measurement of the impact of ARBs (olmesartan 40 mg/d) treatment on renal outcome in 4400 patients with type 2 diabetes without microalbuminuria. Follow-up of this placebo-controlled study will last for 5 years. Conducted in 200 European centers, its results are expected for 2012.
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Affiliation(s)
- S Halimi
- Secteur diabétologie nutrition, Dune (département uro-néphro-endocrinologie), CHU de Grenoble.
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Nakamura H, Inoue T, Arakawa N, Shimizu Y, Yoshigae Y, Fujimori I, Shimakawa E, Toyoshi T, Yokoyama T. Pharmacological and pharmacokinetic study of olmesartan medoxomil in animal diabetic retinopathy models. Eur J Pharmacol 2005; 512:239-46. [PMID: 15840410 DOI: 10.1016/j.ejphar.2005.02.047] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2004] [Revised: 02/23/2005] [Accepted: 02/25/2005] [Indexed: 12/22/2022]
Abstract
A close relationship between the renin-angiotensin system and the pathophysiology of diabetic retinopathy has been suggested, several angiotensin II type 1 receptor (angiotensin AT1 receptor) antagonists being effective in animal models. Therefore, we examined the efficacy of an angiotensin AT1 receptor antagonist, olmesartan medoxomil (CS-866), in animal retinopathy models. In diabetic stroke-prone spontaneously hypertensive (SHRSP) rats, 4-week treatment with CS-866 prevented the elongation of oscillatory potential peaks dose-dependently which almost normalized at 3 mg/kg/day. Next, in oxygen-induced retinopathy mice, CS-866 at 1 mg/kg significantly prevented the retinal neovascularization. In these animal models, plasma concentrations of CS-866 were comparable to the in vitro IC50 value of the angiotensin AT1 receptor. In summary, our data demonstrated that CS-866 was effective in early and late stage retinopathy models through the inhibition of the angiotensin AT1 receptor. These findings suggest the possibility of CS-866 as a therapeutic agent for diabetic retinopathy.
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Affiliation(s)
- Hiroaki Nakamura
- Pharmacology and Molecular Biology Research Laboratories, Sankyo Co., Ltd., 2-58, Hiromachi 1-chome, Shinagawa-ku, Tokyo 140-8710, Japan.
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Yoshida K, Kohzuki M. Clinical and experimental aspects of olmesartan medoxomil, a new angiotensin II receptor antagonist. ACTA ACUST UNITED AC 2005; 22:285-308. [PMID: 15592575 DOI: 10.1111/j.1527-3466.2004.tb00147.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Olmesartan medoxomil is a new orally active angiotensin II (Ang II) type 1 receptor antagonist. It is a prodrug and is rapidly de-esterified during absorption to form olmesartan, the active metabolite. Olmesartan is a potent, competitive and selective Ang II type 1 receptor antagonist. Olmesartan is not metabolized by the cytochrome P-450 and has a dual route of elimination, by kidneys and liver. In patients with essential hypertension olmesartan medoxomil administered once daily at doses of 10-80 mg dose-dependently reduced diastolic blood pressure (DBP). Troughto-peak ratios for both DBP and systolic blood pressure (SBP) were above 50%. At the recommended once-daily starting doses, olmesartan medoxomil (20 mg) was more effective than losartan (50 mg), valsartan (80 mg) or irbesartan (150 mg) in reducing cuff DBP in patients with essential hypertension. The results of cuff SBP and mean 24-h DBP and SBP were similar to those of cuff DBP measurement. In mild-to-moderate hypertensive patients the recommended starting dose of olmesartan medoxomil was as effective as that of amlodipine besylate (5 mg/day) in reducing both cuff and 24-h blood pressure. In lowering DBP olmesartan medoxomil, at 10-20 mg/day, was as effective as atenolol at 50-100 mg/day. In mild-to-moderate hypertensive patients, olmesartan medoxomil, at 5-20 mg once daily, was more effective than captopril at 12.5-50 mg twice daily. At 20-40 mg once daily olmesartan medoxomil was as effective as felodipine, at 5-10 mg once daily. Olmesartan medoxomil has minimal adverse effects with no clinically important drug interactions. Animal studies have shown that olmesartan medoxomil provides a wide range of organ protection. Olmesartan medoxomil ameliorated atherosclerosis in hyperlipidemic animals and ameliorated cardiac remodeling and improved survival in rats with myocardial infarction. Olmesartan medoxomil has renoprotective effects in a remnant kidney model and type 2 diabetes models. Future investigation should reveal whether these beneficial effects of olmesartan medoxomil are applicable to human diseases.
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Affiliation(s)
- Kazunori Yoshida
- Department of Medicine, Furukawa City Hospital, Furukawa, Miyagi 989-6183, Japan.
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Schrijvers BF, De Vriese AS, Flyvbjerg A. From hyperglycemia to diabetic kidney disease: the role of metabolic, hemodynamic, intracellular factors and growth factors/cytokines. Endocr Rev 2004; 25:971-1010. [PMID: 15583025 DOI: 10.1210/er.2003-0018] [Citation(s) in RCA: 242] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
At present, diabetic kidney disease affects about 15-25% of type 1 and 30-40% of type 2 diabetic patients. Several decades of extensive research has elucidated various pathways to be implicated in the development of diabetic kidney disease. This review focuses on the metabolic factors beyond blood glucose that are involved in the pathogenesis of diabetic kidney disease, i.e., advanced glycation end-products and the aldose reductase system. Furthermore, the contribution of hemodynamic factors, the renin-angiotensin system, the endothelin system, and the nitric oxide system, as well as the prominent role of the intracellular signaling molecule protein kinase C are discussed. Finally, the respective roles of TGF-beta, GH and IGFs, vascular endothelial growth factor, and platelet-derived growth factor are covered. The complex interplay between these different pathways will be highlighted. A brief introduction to each system and description of its expression in the normal kidney is followed by in vitro, experimental, and clinical evidence addressing the role of the system in diabetic kidney disease. Finally, well-known and potential therapeutic strategies targeting each system are discussed, ending with an overall conclusion.
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Affiliation(s)
- Bieke F Schrijvers
- Medical Department M/Medical Research Laboratories, Clinical Institute, Aarhus University Hospital, Nørrebrogade 44, DK-8000 Aarhus C, Denmark
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Sada T, Mizuno M. [Pharmacological profiles and clinical effects of olmesartan medoxomil, a novel angiotensin II receptor blocker]. Nihon Yakurigaku Zasshi 2004; 124:257-69. [PMID: 15467259 DOI: 10.1254/fpj.124.257] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
Olmesartan medoxomil is a new angiotensin II receptor blocker (ARB) indicated for the treatment of hypertension. Olmesartan medoxomil is a pro-drug that is converted to the active metabolite olmesartan. Olmesartan does not undergo further metabolism and does not interact with cytochrome P450 enzymes. Olmesartan is a potent ARB with high selectivity for the type 1 (AT(1)) receptor subtype and shows insurmountable antagonism against the AT(1) receptor in vascular tissues. This antagonistic mode, which could be attributed to tight binding of this drug to the receptor, would underlie the potent and persistent action of olmesartan medoxomil in vivo. In fact, oral administration of olmesartan medoxomil produces a potent and long-lasting antihypertensive action without inducing tachycardia. The preventive effects of olmesartan medoxomil on end-organ damage in the kidney, heart, and blood vessels have been demonstrated in various animal models. In clinical studies, olmesartan medoxomil is shown to be well tolerated and have an excellent safety profile that is comparable to that of placebo. Head-to-head comparisons with other ARBs (losartan, valsartan, irbesartan, and candesartan cilexetil) conducted in the United States and Europe have revealed that olmesartan medoxomil is superior to these other ARBs in lowering blood pressure. These facts suggest that olmesartan medoxomil would be beneficial for the treatment of hypertension and other end-organ diseases.
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Affiliation(s)
- Toshio Sada
- Pharmacology and Molecular Biology Research Laboratories, Sankyo Co., Ltd., Tokyo 140-8710, Japan
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