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Lytvyn Y, Bjornstad P, van Raalte DH, Heerspink HL, Cherney DZI. The New Biology of Diabetic Kidney Disease-Mechanisms and Therapeutic Implications. Endocr Rev 2020; 41:5601424. [PMID: 31633153 PMCID: PMC7156849 DOI: 10.1210/endrev/bnz010] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 10/17/2019] [Indexed: 02/07/2023]
Abstract
Diabetic kidney disease remains the most common cause of end-stage kidney disease in the world. Despite reductions in incidence rates of myocardial infarction and stroke in people with diabetes over the past 3 decades, the risk of diabetic kidney disease has remained unchanged, and may even be increasing in younger individuals afflicted with this disease. Accordingly, changes in public health policy have to be implemented to address the root causes of diabetic kidney disease, including the rise of obesity and diabetes, in addition to the use of safe and effective pharmacological agents to prevent cardiorenal complications in people with diabetes. The aim of this article is to review the mechanisms of pathogenesis and therapies that are either in clinical practice or that are emerging in clinical development programs for potential use to treat diabetic kidney disease.
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Affiliation(s)
- Yuliya Lytvyn
- Department of Medicine, Division of Nephrology, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Petter Bjornstad
- Department of Medicine, Division of Nephrology, Department of Pediatrics, Section of Endocrinology, University of Colorado School of Medicine, Aurora, Colorado
| | - Daniel H van Raalte
- Diabetes Center, Department of Internal Medicine, VU University Medical Center, Netherlands
| | - Hiddo L Heerspink
- The George Institute for Global Health, Sydney, Australia.,Department of Clinical Pharmacology, University of Groningen, Groningen, Netherlands
| | - David Z I Cherney
- Department of Medicine, Division of Nephrology, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada
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Quantitative Indexes of Leukocytes in Spontaneously Hypertensive Rats During Various Periods of Arterial Hypertension Development. Bull Exp Biol Med 2015; 159:715-7. [DOI: 10.1007/s10517-015-3056-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Indexed: 11/27/2022]
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Abstract
OBJECTIVES To investigate whether NADPH oxidase 2 (NOX2), a major source of reactive oxygen species (ROS), contributes to the emergence of arterial hypertension in a murine model of sleep apnea. BACKGROUND Obstructive sleep apnea (OSA) is a risk factor for arterial hypertension and it is linked to oxidative stress. METHODS C57BL/6J mice were exposed to chronic intermittent hypoxia (CIH) for 6 weeks (5 days/week, 8 h/day, alternating cycles of hypoxia and normoxia, each lasting 120 s, nadir FiO2: 7%). Blood pressure was monitored by telemetric catheters implanted into the abdominal aorta. Pharmacological inhibition of NOX by apocynin and NOX2-deficient mice were used to assess the role of NOX in CIH-induced arterial hypertension. NOX2 gene expression was measured by real-time PCR in different cardiovascular tissues. RESULTS When compared with room air conditions, wild-type mice showed significant blood pressure elevations after exposure to CIH. This response was attenuated after treating animals with apocynin and in NOX2 (=gp91) knockout mice, whereas NOX2 was not upregulated in the heart, aorta, and femoral/carotid arteries of CIH mice. CONCLUSION We suggest that the CIH-induced arterial hypertension is mediated by ROS derived from an activation of NOX2 within cells located outside the cardiovascular system.
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Lee MCI. Assessment of oxidative stress and antioxidant property using electron spin resonance (ESR) spectroscopy. J Clin Biochem Nutr 2012; 52:1-8. [PMID: 23341690 PMCID: PMC3541412 DOI: 10.3164/jcbn.12-58] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Accepted: 10/10/2012] [Indexed: 01/17/2023] Open
Abstract
The pathophysiology of hypertension or stroke is associated with an excess of ROS generation in the vascular system, and results in induction of various pathological cascades of cerebrovascular damage. We have demonstrated that electron spin resonance methods using a spin trap or spin probe will be useful for understanding redox status under conditions of oxidative stress in the spontaneously hypertensive rat or stroke-prone spontaneously hypertensive rat brain. We have used electron spin resonance imaging and noninvasive L-band electron spin resonance to characterize the higher degree of brain oxidative stress in the stroke-prone spontaneously hypertensive rat and spontaneously hypertensive rat than in the Wistar-Kyoto rat brain, and the lower extent of oxidative stress in the spontaneously hypertensive rat than in the stroke-prone spontaneously hypertensive rat brain. Indeed, we may be able to confirm propofol medium-chain triglyceride/long-chain triglyceride (MCT/LCT) as neuroprotective anesthesia and crocetin as antioxidant food factor against human stroke after screening for antioxidant properties in stroke models such as stroke-prone spontaneously hypertensive rat. Thus, our electron spin resonance biomedical application suggests that it could be used to assess antioxidant effects on oxidative stress in the brain using spontaneously hypertensive rat and stroke-prone spontaneously hypertensive rat. We hope that further advances in the instrumentation used for electron spin resonance imaging and the development of optimized nontoxic spin probes will make this technology even more promising for novel clinical prediction or noninvasive diagnosis of human stroke. After screening drugs or foods for antioxidant property using in vitro or in vivo electron spin resonance assessment, it will be possible to find and develop novel drugs or food factors with such properties for the prevention of stroke in the near future.
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Affiliation(s)
- Masaichi-Chang-Il Lee
- Department of Clinical Care Medicine, Division of Pharmacology and ESR Laboratories, Kanagawa Dental College, 82 Inaoka-cho, Yokosuka, Kanagawa 238-8580, Japan
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Matsubara M, Akizuki O, Ikeda JI, Saeki K, Yao K, Sasaki K. Benidipine, an anti-hypertensive drug, inhibits reactive oxygen species production in polymorphonuclear leukocytes and oxidative stress in salt-loaded stroke-prone spontaneously hypertensive rats. Eur J Pharmacol 2007; 580:201-13. [PMID: 18048030 DOI: 10.1016/j.ejphar.2007.10.072] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2007] [Revised: 10/15/2007] [Accepted: 10/18/2007] [Indexed: 01/22/2023]
Abstract
Oxidative stress is associated with exacerbation of renal injuries in hypertension. In clinical studies benidipine hydrochloride (benidipine), a dihydropyridine calcium channel blocker with antioxidant activity, reduced oxidative stress. However, the mechanism of suppression of oxidative stress remains to be fully characterized. Reactive oxygen species production by polymorphonuclear leukocyte plays important pathological roles in hypertension. Therefore, we examined the effects of benidipine both on reactive oxygen species production of human polymorphonuclear leukocytes and oxidative stress of an animal model. Human peripheral polymorphonuclear leukocytes or polymorphonuclear leukocyte-like differentiated HL-60 cells were used to examine effects of benidipine (0.1-30 microM) on formyl-Met-Leu-Phe-induced reactive oxygen species production, calcium mobilization, NADPH oxidase activation and phosphorylation of protein kinase C substrates. High-salt (8% NaCl) loaded stroke-prone spontaneously hypertensive rats were treated with or without benidipine (1, 3, 10 mg/kg/day) for 2 weeks, and thiobarbituric acid reactive substances, a plasma oxidative stress marker, and renal expression of oxidative stress-induced genes were measured. Benidipine concentration-dependently suppressed formyl-Met-Leu-Phe-induced reactive oxygen species production in polymorphonuclear leukocytes more potently than other calcium channel blockers such as amlodipine, azelnidipine, nitrendipine and nifedipine. Benidipine partially inhibited all of intracellular Ca(2+) elevation, protein kinase C activation and NADPH oxidase activation. Salt loading in stroke-prone spontaneously hypertensive rats augmented plasma thiobarbituric acid reactive substances levels; renal dysfunction; and renal expression of transforming growth factor-beta, collagen I and collagen III mRNAs; which were attenuated by benidipine treatment. These results indicate that benidipine prevents the polymorphonuclear leukocyte-derived reactive oxygen species production, which is due at least in part to its antioxidant action and inhibition of Ca(2+)/protein kinase C/NADPH oxidase signaling. The attenuation of reactive oxygen species production might contribute to the drug's reduction of oxidative stress and renal injuries in hypertension.
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Affiliation(s)
- Masahiro Matsubara
- Pharmaceutical Research Center, Kyowa Hakko Kogyo Co., Ltd., 1188 Shimotogari, Sunto-gun, Shizuoka 411-8731, Japan.
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The polymorphonuclear leukocyte contributes to the development of hypertension in the Sabra rat. J Hypertens 2007; 25:2249-56. [DOI: 10.1097/hjh.0b013e3282dd79b6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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DeLano FA, Parks DA, Ruedi JM, Babior BM, Schmid-Schönbein GW. Microvascular display of xanthine oxidase and NADPH oxidase in the spontaneously hypertensive rat. Microcirculation 2006; 13:551-66. [PMID: 16990214 DOI: 10.1080/10739680600885152] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE Oxygen free radical production in hypertension may be associated with elevated arteriolar tone and organ injury. Previous results suggest an enhanced level of oxygen free radical formation in microvascular endothelium and in circulating neutrophils associated with xanthine oxidase activity in the spontaneously hypertensive rats (SHR) compared with their normotensive controls, the Wistar Kyoto rats (WKY). The aim of this study was to gain more detailed understanding of where oxidative enzymes are located in the microcirculation. METHODS An approach was developed to delineate the cellular distribution of two selected oxidative enzymes, xanthine oxidase and nicotinamide adenine dinucleotide phosphate (NADPH) dependent oxidase (protein 67-kDa fraction). Immunolabeling with peroxidase substrate was utilized, which permits full delineation of the primary antibody in all microvascular structures of the mesentery. RESULTS Xanthine oxidase is present in the endothelium of all segments of the microcirculation, in mast cells, and in parenchymal cells of the mesentery. NADPH oxidase can be detected in the endothelium, leukocytes, and mast cells and with lower levels in parenchymal cells. The mesentery of WKY and SHR has similar enzyme distributions with enhancements on the arteriolar and venular side of the microcirculation that coincide with the sites of enhanced free radical production recently reported. Immune label measurements under standardized conditions indicate that both enzymes are significantly enhanced in the SHR. Adrenalectomy, which serves to reduce the blood pressure and free radical production of the SHR to normotensive levels, leads to a reduction of NADPH and xanthine oxidase to normotensive levels, while supplementation of adrenalectomized SHR with dexamethasone significantly increases the oxidase expression in several parts of the microcirculation to levels above the WKY rats. CONCLUSION The results indicate that enhanced expression of NADPH and xanthine oxidase in the SHR depends on an adrenal pathway that is detectable in the arteriolar and venular network at high and low pressure regions of the circulation.
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Affiliation(s)
- Frank A DeLano
- Department of Bioengineering and The Whitaker Institute for Biomedical Engineering, University of California, San Diego, La Jolla, 92093-0412, USA
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Maeda K, Yasunari K, Watanabe T, Nakamura M. Oxidative stress by peripheral blood mononuclear cells is increased in hypertensives with an extreme-dipper pattern and/or morning surge in blood pressure. Hypertens Res 2006; 28:755-61. [PMID: 16419649 DOI: 10.1291/hypres.28.755] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Because oxidative stress and inflammation are known to play important roles in the pathogenesis of cardiovascular events that occur most frequently in the morning, we studied the association between reactive oxygen species (ROS) formation by polymorphonuclear leukocytes (PMNs) or mononuclear cells (MNCs) and morning blood pressure (BP) rhythm. A total of 31 hypertensives in whom ambulatory BP monitoring was performed participated in this study. They were first divided into three groups according to their nocturnal BP rhythm (non-dippers, dippers and extreme dippers), and then into two groups according to their morning BP change (surge-type and sustained-type). ROS formation by PMNs and MNCs was measured by gated flow cytometry. C-reactive protein and traditional risk factors such as age, gender, body mass index, hemoglobin A1c, and total cholesterol were also measured. ROS formation by MNCs was significantly increased in extreme dippers (vs. dippers, p<0.05, n=11) and in morning BP surge-type hypertensives (vs. sustained-type, p<0.05, n=13). In patients who were both extreme dippers and morning BP surge-types, ROS formation by MNCs was significantly higher than that in other groups. These results suggest that both extreme dippers and morning BP surge-type hypertensives may suffer increased ROS formation by MNCs, and that increased ROS formation by MNCs may underlie morning strokes.
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Affiliation(s)
- Kensaku Maeda
- Department of Medicine and Cardiology, Osaka City University Graduate School of Medicine, Osaka, Japan
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Sánchez M, Galisteo M, Vera R, Villar IC, Zarzuelo A, Tamargo J, Pérez-Vizcaíno F, Duarte J. Quercetin downregulates NADPH oxidase, increases eNOS activity and prevents endothelial dysfunction in spontaneously hypertensive rats. J Hypertens 2006; 24:75-84. [PMID: 16331104 DOI: 10.1097/01.hjh.0000198029.22472.d9] [Citation(s) in RCA: 213] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND AND OBJECTIVE Several studies have found that chronic treatment with the dietary flavonoid quercetin lowers blood pressure and restores endothelial dysfunction in hypertensive animal models. We hypothesized that increased endothelial nitric oxide synthase (eNOS) and/or decreased nicotinamide adenine dinucleotide phosphate (NADPH) oxidase protein expression and activity, and reduced reactive oxygen species might be involved in the improvement of endothelial function induced by quercetin in spontaneously hypertensive rats (SHR). DESIGN AND METHODS Male SHR and Wistar-Kyoto (WKY) rats (5 weeks old) were treated with quercetin (10 mg/kg) or vehicle for 13 weeks. Changes in vascular expression of eNOS, caveolin-1 and p47 were analysed by Western blot, eNOS activity by conversion of [H]arginine to L-[H]citrulline, and NADPH oxidase activity by NADPH-enhanced chemoluminescence of lucigenin. RESULTS In SHR, quercetin reduced the increase in blood pressure and heart rate and enhanced the endothelium-dependent aortic vasodilation induced by acetylcholine, but had no effect on the endothelium-independent response induced by nitroprusside. However, quercetin had no effect on endothelium-dependent vasoconstriction and aortic thromboxane B2 production. Compared to WKY, SHR showed upregulated eNOS and p47 protein expression, downregulated caveolin-1 expression, increased NADPH-induced superoxide production but, paradoxically, eNOS activity was reduced. Chronic quercetin treatment prevented all these changes in SHR. In WKY, quercetin had no effect on blood pressure, endothelial function or the expression or activity of the proteins analysed. CONCLUSIONS Enhanced eNOS activity and decreased NADPH oxidase-mediated superoxide anion (O2) generation associated with reduced p47 expression appear to be essential mechanisms for the improvement of endothelial function and the antihypertensive effects of chronic quercetin.
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Affiliation(s)
- Manuel Sánchez
- Department of Pharmacology, School of Pharmacy, University of Granada, Granada, Spain
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Sui H, Wang W, Wang PH, Liu LS. Protective effect of antioxidant ebselen (PZ51) on the cerebral cortex of stroke-prone spontaneously hypertensive rats. Hypertens Res 2005; 28:249-54. [PMID: 16097369 DOI: 10.1291/hypres.28.249] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
An increase in reactive oxygen species has been shown to play a role in perpetuating hypertension and cerebral injury in stroke-prone spontaneously hypertensive rats (SHRsp). Lipid peroxidation in the cerebral cortex is much more intense in SHRsp after establishment of severe hypertension as compared to that in normotensive Wistar-Kyoto rats (WKY). Cortical neurons from SHRsp are more vulnerable to hypoxia and hyponutritional conditions. We sought to investigate whether long-term administration of seleno-glutathione peroxidase mimic ebselen (PZ51) would have a protective effect on cortical neurons in SHRsp, and, if so, the possible mechanisms of this effect. Twenty-two 8-week-old SHRsp were randomized into a PZ51 group and control group. Age-matched WKY were used as normal controls. We examined the levels of malonaldehyde (MDA) and nitric oxide (NO) in the cerebral cortex (CC) homogenate, detected the three isoforms of nitric oxide synthase (NOS) by Western blotting, and examined cortical neurons by transmission electron microscopy. The results showed that PZ51 treatment significantly decreased both MDA and NO in the CC, inhibited inducible nitric oxide synthase (iNOS) protein expression, and alleviated the damage to cortical neurons compared to the findings for the control group. In conclusion, the present study showed that PZ51 administration suppressed lipid peroxidation and inhibited iNOS protein expression in CC homogenate, and it was suggested that these mechanisms may play a role in the protective effects of PZ51 on cortical neurons of SHRsp.
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Affiliation(s)
- Hui Sui
- Cardiovascular Institute and Fuwai Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, No167 BeiLishi Road, Xicheng District, Beijing 100037, P.R. China.
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Yasunari K, Maeda K, Nakamura M, Watanabe T, Yoshikawa J. Benidipine, a long-acting calcium channel blocker, inhibits oxidative stress in polymorphonuclear cells in patients with essential hypertension. Hypertens Res 2005; 28:107-12. [PMID: 16025736 DOI: 10.1291/hypres.28.107] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
To study the relationship between blood pressure and oxidative stress in leukocytes, the effect of benidipine on these variables was compared with that of a placebo. Hypertensive patients were randomly assigned benidipine 4 mg (n=40) or placebo (n=40), and treated for 6 months. Oxidative stress in polymorphonuclear cells (PMNs) was measured by gated flow cytometry. There was a significant relationship between systolic or diastolic arterial pressure and reactive oxygen species (ROS) formation by PMNs in the benidipine group (r=0.61, p<0.01) and in the placebo group (r=0.58, p<0.01). After administration of 4 mg benidipine, ROS formation by PMNs fell by 32 arbitrary units (n=40, p<0.01). After administration of placebo, ROS formation by PMNs decreased by 0.6 arbitrary units (n=40, p=0.31) (p<0.01 for differing treatment effects). There was a significant relationship between the decrease in systolic arterial pressure and the decrease in ROS formation by PMNs in the benidipine group (r=0.52, p<0.01), but not in the placebo group (r=-0.08, p=0.61). There was also a significant relationship between the decrease in diastolic arterial pressure and decrease in ROS formation by PMNs in the benidipine group (r=0.65, p<0.01) but not in the placebo group (r=-0.09, p=0.59). In hypertensive patients, we observed a significant relationship between systolic or diastolic blood pressure and ROS formation by PMNs, and found that benidipine decreased oxidative stress in PMNs of hypertensive patients, at least in part by decreasing blood pressure.
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Affiliation(s)
- Kenichi Yasunari
- Department of General Medicine and Cardiology, Graduate School of Medicine, Osaka City University, Osaka, Japan.
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Maeda K, Yasunari K, Sato EF, Inoue M. Enhanced oxidative stress in neutrophils from hyperlipidemic guinea pig. Atherosclerosis 2005; 181:87-92. [PMID: 15939058 DOI: 10.1016/j.atherosclerosis.2004.12.044] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2003] [Revised: 07/06/2004] [Accepted: 12/02/2004] [Indexed: 10/25/2022]
Abstract
Inhibitors of 3-hydroxy-3-methylglutaryl CoA (HMG-CoA) reductase are antilipidemic agents (statins) widely used for the prevention of cardiovascular diseases. Recent studies have suggested that the overall benefits of statin therapy cannot be accounted for solely by its antilipidemic effect. To obtain further insight into the mechanism of action of statins, we studied the effect of pitavastatin on the generation of reactive oxygen species (ROS) by peritoneal polymorphonuclear leukocytes (PMN) obtained from control and hyperlipidemic guinea pigs. Flow cytometric analysis revealed that the amount of ROS generated by PMN from the hyperlipidemic animals that had been administered a laurate-containing diet (LD) for 4 weeks was larger than that from the normal diet (ND) group (837% increase, ND; 82.17 arbitrary units, LD; 688.10 arbitrary units, P < 0.01, n = 6). Administration of pitavastatin to the LD group significantly decreased plasma levels of total cholesterol (TC) and low-density lipoprotein (LDL) with a reduction in ROS generation by PMN (19% decrease, LD control; 688.10 arbitrary units, LD + pitavastatin; 556.87 arbitrary units, P < 0.01, n = 6). Western blotting analysis revealed that the expression of protein kinase C alpha (PKC alpha) and betaI was higher in PMN from the LD group than in PMN from the ND group (PKC alpha; 74% increase, PKC betaI; 339% increase, P < 0.05, n = 4, respectively). Furthermore, expression of NADPH oxidase gp91phox in PMN from the LD group was higher than that in PMN from the ND group (18% increase, P < 0.05, n = 4). By administration of pitavastatin to the LD group, the expression of PKC alpha, betaI and gp91phox was suppressed compared with the control LD group (PKC alpha; 41% decrease, PKC beta; 28% decrease, gp91phox; 56% decrease, P < 0.05, n = 4, respectively). These results indicate that PMN from hyperlipidemic animals is associated with an accelerated respiratory burst of ROS by increasing the expression of PKC alpha, betaI and gp91phox, and pitavastatin inhibits this by suppressing the expression of those proteins.
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Affiliation(s)
- Kensaku Maeda
- Department of Biochemistry and Molecular Pathology, Osaka City University Medical School, Abeno-ku, Japan.
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Lee MCI, Shoji H, Miyazaki H, Yoshino F, Hori N, Toyoda M, Ikeda Y, Anzai K, Ikota N, Ozawa T. Assessment of Oxidative Stress in the Spontaneously Hypertensive Rat Brain Using Electron Spin Resonance (ESR) Imaging and in Vivo L-Band ESR. Hypertens Res 2004; 27:485-92. [PMID: 15302985 DOI: 10.1291/hypres.27.485] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
This study examined the blood brain barrier (BBB)-permeable nitroxyl compound, 3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl (MC-PROXYL), as a spin probe for the assessment of oxidative stress in the brain by electron spin resonance (ESR) imaging and in vivo L-band ESR. Preliminary comparisons were made by ESR imaging of MC-PROXYL in the isolated brains of normal Wistar-Kyoto rats (WKY), spontaneously hypertensive rats (SHR), and stroke prone SHR (SHRSP). The decay of the ESR images of MC-PROXYL in the isolated brains was faster in SHR than in normal WKY, but was only moderate in SHRSP. In addition, the decay rate of MC-PROXYL in the heads of live rats, as measured noninvasively by L-band ESR, was faster in SHR than in WKY, and was slower in SHR than in SHRSP. Taken together, our data suggest that the oxidative stress of SHR is not as high as that in high oxidative stress animal models such as SHRSP. This is the first study to present reconstructed 3D images of the distribution of MC-PROXYL in the isolated SHR brain. The ESR technique employed herein appears to be a powerful tool for evaluating oxidative stress and for detecting the region of oxidative stress in the brain of SHR.
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Affiliation(s)
- Masaichi-Chang-Il Lee
- Department of Clinical Care Medicine, Division of Pharmacology and ESR Laboratories, Kanagawa Dental College, Yokosuka, Japan
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