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Characteristics of anginal patients with high resting myocardial blood flow measured with N-13 ammonia PET/CT. Nucl Med Commun 2016; 36:619-24. [PMID: 25734541 DOI: 10.1097/mnm.0000000000000293] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
OBJECTIVES We hypothesized that anginal patients with low coronary flow reserve (CFR) could have variable clinical features according to resting myocardial blood flow (MBF). Therefore, we analyzed the clinical and imaging characteristics according to resting MBF in anginal patients. METHODS We enrolled 70 patients who underwent N-13 ammonia PET-computed tomography (CT) for evaluation of angina. Resting and stress MBF values were obtained and resting MBF was corrected with rate-pressure product to exclude the effect of heart rate and blood pressure on resting MBF. Clinical and imaging characteristics were compared on the basis of MBF and CFR. RESULTS Among patients with CFR less than 2.0, those with high resting MBF (≥1.0 ml/min/g) had significantly fewer number of smokers, were younger, had lower Agatston calcium scores, and had less coronary stenosis compared with those with low resting MBF (<1.0 ml/min/g). In contrast, there was no significant difference in clinical or imaging findings according to resting MBF when compared among all patients or within those with CFR greater than or equal to 2.0. The subgroup analysis of patients with CFR less than 2.0 revealed lower Agatston calcium score and less coronary stenosis in patients with high resting MBF regardless of stress MBF. CONCLUSION High resting MBF is associated with a lower rate of smoking, younger age, less coronary calcium burden, and less coronary stenosis compared with low resting MBF in anginal patients with low CFR. Moreover, in these patients, favorable angiographic features were mainly associated with high resting MBF, irrespective of stress MBF. Therefore, resting MBF should be reviewed to validate the clinical significance of low CFR measured by N-13 ammonia PET/CT especially in anginal patients showing low CFR.
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Abstract
The aim of this review article is to summarize the current knowledge about mechanisms that connect blood pressure regulation and hypercholesterolemia, the mutual interaction between hypertension and hypercholesterolemia, and their influence on atherosclerosis development. Our research shows that at least one-third of the population of Western Europe has hypertension and hypercholesterolemia. Several biohumoral mechanisms could explain the relationship between hypertension and hypercholesterolemia and the association between these risk factors and accelerated atherosclerosis. The most investigated mechanisms are the renin-angiotensin-aldosterone system, oxidative stress, endothelial dysfunction, and increased production of endothelin-1. Arterial hypertension is frequently observed in combination with hypercholesterolemia, and this is related to accelerated atherosclerosis. Understanding the mechanisms behind this relationship could help explain the benefits of therapy that simultaneously reduce blood pressure and cholesterol levels.
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Vaspin increases nitric oxide bioavailability through the reduction of asymmetric dimethylarginine in vascular endothelial cells. PLoS One 2012; 7:e52346. [PMID: 23284999 PMCID: PMC3532208 DOI: 10.1371/journal.pone.0052346] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Accepted: 11/12/2012] [Indexed: 11/19/2022] Open
Abstract
Vaspin is an adipocytokine recently identified in the visceral adipose tissue of diabetic rats and having anti-diabetic effects. We have recently shown that vaspin has anti-atherogenic effect through Akt-mediated inhibition of endothelial cell apoptosis. Decreased activity of endothelial nitric oxide synthase (eNOS) plays an important role in the pathogenesis of atherosclerosis. Asymmetric dimethylarginine (ADMA) is a well-known endogenous competitive inhibitor of eNOS and risk factor of cardiovascular diseases. The aim of this study was to examine whether vaspin might protect against atherosclerosis through its beneficial effects on the ADMA-eNOS system. Treatment of vaspin significantly increased NO secretion from endothelial cells and isolated aorta from Sprague-Dawley (SD) rats. Furthermore, treatment of vaspin prevented fatty acid-induced decrease in endothelium-dependent vasorelaxation in isolated aorta of SD rat. For the mechanism of vaspin-induced NO biosynthesis, vaspin activated the STAT3 signaling pathway and stimulated eNOS phosphorylation (Ser 1177), a marker of eNOS activation, through STAT3-dependent mechanism. Furthermore, vaspin treatment increased the expression of dimethylarginine dimethylaminohydrolase (DDAH) II, the responsible enzyme for the degradation of ADMA, leading to a reduction in ADMA levels. Vaspin-induced increase in DDAH II gene expression was through STAT3-mediated stimulation of DDAH II promoter activity. These results suggest that vaspin increases eNOS activity by reducing ADMA level through STAT3-mediated regulation of DDAH II expression. Our findings provide a novel molecular mechanism of antiatherogenic actions of vaspin.
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Hui Y, Wong M, Kim JO, Love J, Ansley DM, Chen DDY. A new derivatization method coupled with LC-MS/MS to enable baseline separation and quantification of dimethylarginines in human plasma from patients to receive on-pump CABG surgery. Electrophoresis 2012; 33:1911-20. [PMID: 22740479 DOI: 10.1002/elps.201100536] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Asymmetric dimethylarginine (ADMA) is an inhibitor of nitric oxide synthase and a risk factor for cardiovascular events. We have developed a new derivatization method to enable baseline separation of the regio-isomers, ADMA, and symmetric dimethylarginine (SDMA), within 15 min on a C18 reverse phase column. Reacting naphthalene-2,3-dicarboxaldehyde with ADMA and SDMA in the presence of 2-mercaptoethanol produces corresponding 2,3-dihydro-benzo[f]isoindol-1-ones that are more stable than previously reported ortho-phthaldialdehyde and 2-mercaptoethanol derivatives. LC-MS/MS quantitation of these derivatives can be used to determine ADMA and SDMA concentrations in the plasma of patients to receive on-pump coronary artery bypass grafting (CABG) surgery. The LOD, LOQ and lower LOQ (LLOQ) of this method were determined to be 2.6, 8.7, and 25 nM for ADMA, and 2.5, 8.3, and 25 nM for SDMA, respectively, with consumption of only 50 μL of plasma. The relative standard deviations and relative errors of the intraday and interday determinations, as measurements of reproducibility and accuracy, are all within 15%. The ADMA and SDMA concentrations in patient plasma are 298.1 ± 11.2 nM (mean ± S.E.M., n = 123) and 457.7 ± 19.8 nM (mean ± S.E.M., n = 123), respectively. Upon unblinding of our clinical trial, these predetermined values might explain patient clinical outcomes associated with on-pump CABG surgery, as ADMA is known to inhibit nitric oxide production. Furthermore, this derivatization reaction in conjunction with LC-MS/MS analysis may open a venue to explore alternative chemical labeling modes for LC-MS/MS applications, such as analysis of other amino acids, metabolites, and peptides containing primary amine group(s).
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Affiliation(s)
- Yu Hui
- Department of Chemistry, University of British Colombia, Vancouver, BC, Canada
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Ishida K, Geshi T, Nakano A, Uzui H, Mitsuke Y, Okazawa H, Ueda T, Lee JD. Beneficial effects of statin treatment on coronary microvascular dysfunction and left ventricular remodeling in patients with acute myocardial infarction. Int J Cardiol 2012; 155:442-7. [DOI: 10.1016/j.ijcard.2011.11.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Revised: 09/21/2011] [Accepted: 11/04/2011] [Indexed: 10/14/2022]
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Ozdoğan S, Kaman D, Simşek BÇ. Effects of coenzyme Q10 and α-lipoic acid supplementation in fructose fed rats. J Clin Biochem Nutr 2011; 50:145-51. [PMID: 22448096 PMCID: PMC3303477 DOI: 10.3164/jcbn.11-47] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2011] [Accepted: 05/21/2011] [Indexed: 12/03/2022] Open
Abstract
This study was conducted to investigate the effects of α-lipoic acid and coenzyme Q10 on plasma levels of lipids, asymmetric dimethylarginine, oxidative stress in fructose fed rats which provide a model of dietary-induced insulin resistance and to evaluate vascular changes developing in these rats by histologically. Male Sprague Dawley rats were used in this study. The animals were divided into 4 groups. Group 1 did not receive any medication and served as a control. Group 2 received a regular diet and water ad libitum and fructose was administered as % 10 solution in drinking water. Group 3 received α-lipoic acid (100 mg/kg/day) i.p. for 5 weeks and Group 4 received coenzyme Q10 (10 mg/kg/day) i.p. for 5 weeks. For determination of plasma asymmetric dimethylarginine, glutathione and malondialdehyde levels, high-performance liquid chromatography system was used. Homeostatic model assessment as a measure of insulin resistance was calculated. Lipid profile measurements were determined using enzymatic assay on an Auto analyzer. The high fructose diet was significantly associated with an increase in levels of plasma LDL, VLDL and total cholesterol and decrease in level of HDL cholesterol. Plasma asymmetric dimethylarginine, malondialdehyde and glutathione levels were also increase in these rats. α-lipoic acid or coenzyme Q10 supplementation was found to have some positive effect on these parameters. These findings were also demonstrated by morphological observation of the aorta. We demonstrated that administration of α-lipoic acid and coenzyme Q10 notably suppresses oxidative and nitrative stress, hyperinsulinemia, insulin resistance developing in fructose fed rats, a model of metabolic syndrome (MS). These positive effects of α-lipoic acid or coenzyme Q10 can be attributed to its antioxidant activity.
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Affiliation(s)
- Serhat Ozdoğan
- Department of Biochemistry, Firat University Firat Medical Center, Firat University Medical Hospital, 23100, Elazig, Turkey
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Zhang Q, Chen N, Qiu W, Xu X, Wang D, Tsao PS, Jin H. Asymmetric dimethylarginine impairs fibrinolytic activity in human umbilical vein endothelial cells via p38 MAPK and NF-κB pathways. Thromb Res 2011; 128:42-6. [PMID: 21429569 DOI: 10.1016/j.thromres.2011.02.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2010] [Revised: 02/18/2011] [Accepted: 02/20/2011] [Indexed: 02/05/2023]
Abstract
INTRODUCTION Asymmetric dimethylarginine (ADMA) is a potent endogenous inhibitor of nitric oxide (NO) synthase. An increased synthesis and/or a reduced catabolism of ADMA might contribute to the onset and progression of thrombosis. The present study was designed to evaluate the effect of ADMA on fibrinolytic factors in endothelial cells, and to investigate the cellular mechanisms. MATERIALS AND METHODS Human umbilical vein endothelial cells (HUVECs) were treated with different concentrations of ADMA for various periods; Then HUVECs were preincubated with NO precursor (L-arginine), MAPK inhibitors, or NF-κB inhibitor (PDTC) before ADMA treatment to repeat the experiment. Protein levels of tissue plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1), and NF-κB activity were measured by ELISA; mRNA levels of tPA and PAI-1 were assayed by qRT-PCR; The activation of MAPK was characterized by western blot analysis. RESULTS (1) ADMA decreased tPA antigen levels in time- and concentration-dependent manners, with the maximum effect of 30 μmol/L ADMA for 48h (control 109.01 ± 4.15 ng/ml vs ADMA 86.76 ± 5.95 ng/ml, p<0.01); (2) 30 μmol/L ADMA elevated antigen levels of PAI-1 in a time-dependent manner, with the maximum effect of 30 μmol/L ADMA for 48 h (control 2721.12 ± 278.02 ng/ml vs. ADMA 3435.78 ± 22.33ng/ml, p<0.05); (3) ADMA reduced tPA mRNA levels and increased PAI-1 mRNA levels; (4) L-arginine, SB203580 (p38 MAPK inhibitor) and PDTC attenuated the effects of ADMA on tPA and PAI-1 significantly. (5) ADMA induced a rapid phosphorylation of p38 MAPK, and stimulated NF-κB activity greatly. CONCLUSIONS ADMA may accelerate thrombosis development by impairing fibrinolytic activity in vascular via inhibiting nitric oxide production and then activating its downstream p38 MAPK and NF-κB pathways.
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Affiliation(s)
- Qin Zhang
- The First Affiliated Hospital of Shantou University Medical College, Shantou, 515041, China
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Lee WJ, Kim SW, Kim GH, Han SM, Won JC, Jung CH, Park HS, Choi DS, Lee KU, Park JY. Alpha-lipoic acid activates dimethylarginine dimethylaminohydrolase in cultured endothelial cells. Biochem Biophys Res Commun 2010; 398:653-8. [PMID: 20603107 DOI: 10.1016/j.bbrc.2010.06.127] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Accepted: 06/30/2010] [Indexed: 11/30/2022]
Abstract
Asymmetric dimethylarginine (ADMA) is a risk factor of cardiovascular diseases. alpha-Lipoic acid (ALA) was shown to improve vascular dysfunction, and to decrease plasma ADMA level. In this study, we investigated whether ALA activates dimethylarginine dimethylaminohydrolase (DDAH), the metabolizing enzyme of ADMA, in cultured endothelial cells. ALA significantly decreased ADMA level in culture media of endothelial cells. ALA increased the gene expression and activity of DDAH, and signal transducer and activator of transcription (STAT)3 phosphorylation. Transfection of STAT3 increased DDAH II promoter activity, and ALA amplified it. ALA-induced increase in DDAH II promoter activity was attenuated in the promoter that had mutation in putative STAT3-binding site. These results suggest that ALA reduces ADMA level by enhancing DDAH activity and DDAH II gene expression, thus providing a novel mechanism by which ALA regulates endothelial function.
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Affiliation(s)
- Woo Je Lee
- Department of Internal Medicine, University of Ulsan College of Medicine, Seoul, Republic of Korea
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Wanby P, Brattström L, Brudin L, Hultberg B, Teerlink T. Asymmetric dimethylarginine and total homocysteine in plasma after oral methionine loading. Scand J Clin Lab Invest 2009; 63:347-53. [PMID: 14599157 DOI: 10.1080/00365510310002040] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND Elevation of homocysteine (Hcy) and asymmetric dimethylarginine (ADMA) in plasma are believed to be involved in the pathogenesis of cardiovascular disease (CVD). In humans, oral methionine loading results in acute elevation of plasma Hcy. This is associated with impaired NO-dependent vasodilatation, a mechanism that may explain the relationship between elevated Hcy and risk of CVD. ADMA, an endogenous competitive inhibitor of NO-synthase, may be elevated in plasma of patients with CVD. It was proposed that ADMA is synthesized in a methionine-dependent reaction which also forms Hcy. In this study plasma total homocysteine (tHcy) and ADMA concentrations were measured before and after oral methionine loading of human subjects. METHODS Plasma tHcy and ADMA levels were measured in 12 healthy males (age 32-58 years) before and after oral loading with L-methionine (100 mg/kg body weight in orange juice). RESULTS At noon, 4 h after methionine loading, tHcy and ADMA levels (35.4 +/- 10.9 and 0.80 +/- 0.13 micromol/L, mean +/- SD) were significantly higher than the corresponding values obtained at noon the day before (15.6 +/- 7.4 and 0.63 +/- 0.10 micromol/L, both p<0.001). Noon values 4 h after methionine loading were also significantly higher than values obtained immediately before the methionine load (13.7 +/- 5.9 and 0.66 +/- 0.10 micromol/L, both p<0.001). Reinvestigation of 8 of 12 subjects showed that at 4 and 8 h after compared with levels immediately before methionine loading there was a significant increase in tHcy (28.4 +/- 10.2 and 33.45 +/- 11.1 vs. 10.8 +/- 3.3 micromol/L, both p<0.001). However, the corresponding ADMA levels did not increase (0.73 +/- 0.17 and 0.76 +/- 0.22 vs. 0.70 +/- 0.10 micromol/L, both not significant). CONCLUSIONS No clear evidence was found to support the supposition that methionine-induced hyperhomocysteinaemia may be accompanied by elevated levels of ADMA, an endogenous competitive NO-synthase inhibitor that may represent an alternative pathogenic mechanism for homocysteine-associated impairment of endothelial NO-dependent functions.
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Affiliation(s)
- P Wanby
- Department of Medicine, County Hospital, Kalmar, Sweden
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Paiva H, Kahonen M, Lehtimaki T, Raitakari OT, Jula A, Viikari J, Alfthan G, Juonala M, Laaksonen R, Hutri-Kahonen N. Asymmetric dimethylarginine (ADMA) has a role in regulating systemic vascular tone in young healthy subjects: the cardiovascular risk in young Finns study. Am J Hypertens 2008; 21:873-8. [PMID: 18551100 DOI: 10.1038/ajh.2008.215] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND This study was designed to evaluate whether plasma asymmetric dimethylarginine (ADMA) has any role in predicting hemodynamic responses in clinically healthy young subjects. ADMA, as an endogenous nitric oxide (NO) synthase inhibitor, has been demonstrated to associate with hypertension and vascular reactivity in experimental but not undoubtedly in physiological settings. METHODS A total of 199 subjects aged 31.4 years (range 24-39 years) were studied. Plasma ADMA and symmetric dimethylarginine (SDMA) were assessed by isocratic high-pressure liquid chromatography using precolumn derivatization with o-phtaldialdehyde at baseline. Blood pressure (BP) was measured by casual measurements in the beginning of the study and after a follow-up period of 2.45 +/- 0.42 years (range, 1.86-3.19 years). Hemodynamic regulation was assessed by noninvasive methods after a follow-up. RESULTS Plasma ADMA had a negative association with resting systemic vascular resistance index (SVRI) (r = -0.23, P < 0.01) and pulse wave velocity (PWV) (r = -0.17, P < 0.05) and positive association with cardiac index (CI) (r = 0.21, P < 0.01) after the follow-up. Plasma ADMA had also negative association with responses of SVRI (r = -0.19, P < 0.01) and positive association with CI (r = 0.25, P < 0.001) in a hemodynamic reactivity test. In a multivariate linear model (R2 = 0.20, P < 0.00001), diastolic BP (R = 0.37, P < 0.00001) and ADMA (R = -0.20, P < 0.01) were significant predictors of SVRI. CONCLUSIONS These results suggest that plasma ADMA seems to play a role in the regulation of vascular tone in young healthy subjects.
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Young JM, Strey CH, George PM, Florkowski CM, Sies CW, Frampton CM, Scott RS. Effect of atorvastatin on plasma levels of asymmetric dimethylarginine in patients with non-ischaemic heart failure. Eur J Heart Fail 2008; 10:463-6. [PMID: 18430606 DOI: 10.1016/j.ejheart.2008.03.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2007] [Revised: 03/13/2008] [Accepted: 03/26/2008] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Elevated plasma levels of asymmetric dimethylarginine (ADMA), an endothelial nitric oxide synthase (eNOS) inhibitor, may contribute to endothelial dysfunction in chronic heart failure (CHF). Since statins upregulate eNOS and ameliorate endothelial dysfunction in non-ischaemic CHF, we hypothesized that this may be in part through modification of ADMA. AIM To evaluate the effect of atorvastatin on the relationship between ADMA and endothelial function in non-ischaemic CHF. METHODS Twenty-four patients with CHF (ejection fraction <40%, New York Heart Association Functional Classes II and III) were randomised to atorvastatin treatment (40 mg) or placebo once daily for 6 weeks in a double-blinded, placebo-controlled crossover study. Plasma ADMA and l-arginine levels were measured by HPLC. Endothelial function was assessed by flow-mediated dilatation and invasive forearm plethysmography. RESULTS Post-statin therapy, endothelial function was improved (p<0.05) independent of LDL-cholesterol reductions, but no changes were observed in ADMA levels or the l-arginine to ADMA ratio. There was a trend for ADMA to inversely correlate with endothelial function at baseline. CONCLUSIONS Short-term atorvastatin treatment in non-ischaemic CHF improves endothelial function but has no effect on ADMA or the l-arginine to ADMA ratio. Our finding suggests that the observed statin-induced improvements in endothelial function are likely mediated via alternative pathways.
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Affiliation(s)
- Joanna M Young
- Lipid and Diabetes Research Group, Christchurch Hospital, Christchurch, New Zealand.
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Kawata T, Daimon M, Hasegawa R, Teramoto K, Toyoda T, Sekine T, Yamamoto K, Uchida D, Himi T, Yoshida K, Komuro I. Effect of angiotensin-converting enzyme inhibitor on serum asymmetric dimethylarginine and coronary circulation in patients with type 2 diabetes mellitus. Int J Cardiol 2008; 132:286-8. [PMID: 18083252 DOI: 10.1016/j.ijcard.2007.08.066] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2007] [Accepted: 08/04/2007] [Indexed: 01/12/2023]
Abstract
Measurements of serum asymmetric dimethylarginine (ADMA), an endogenous nitric oxide synthase inhibitor, and coronary flow velocity reserve (CFVR) using transthoracic Doppler echocardiography were performed at baseline and after 4 weeks of temocapril therapy (2 mg/day) in 18 patients with type 2 diabetes. Although blood pressure, fasting blood sugar and lipid profiles remained unchanged, serum ADMA concentrations decreased significantly (0.51+/-0.08 to 0.46+/-0.07 micromol/l, p<0.01) and CFVR increased significantly (2.78+/-0.36 to 3.35+/-0.46, p<0.001) after the treatment. Moreover, a strong correlation was observed between the difference of ADMA and that of CFVR (r=-0.80, p<0.001). Temocapril reduced serum ADMA concentrations, improved CFVR beyond its blood pressure lowering effect. Our results suggest that decrease in ADMA by temocapril treatment is related to improvement of coronary circulation as determined by CFVR in patients with type 2 diabetes.
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Vascular oxidative stress is associated with insulin resistance in hyper-reninemic nonmodulating essential hypertension. J Hypertens 2008; 25:2434-40. [PMID: 17984665 DOI: 10.1097/hjh.0b013e3282f03597] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
BACKGROUND Nonmodulating hypertension (NMHT) is a high-renin subtype of salt-sensitive hypertension due to renal hemodynamic alterations. AIMS To evaluate, in NMHT, whether the increased oxidative stress, which interferes with endothelial function, could be the consequence of an elevated renin-angiotensin activity and insulin resistance. METHODS Fourteen patients with NMHT and 12 with modulating hypertension (MHT) were included. Plasma renin activity (PRA) and glucose/insulin tolerance test were performed and homeostasis model assessment (HOMA) index and areas under the curves (AUC) calculated. Urinary nitrites and nitrates (NOx), urinary cyclic guanosine monophosphate (cGMP) activity, urinary isoprostanes and plasma nitrotyrosine levels were also measured. RESULTS PRA was higher in NMHT than MHT. In addition, L-arginine infusion increased effective renal plasma flow in MHT but not in NMHT. Insulin levels were higher in NMHT both at fasting and at 120 min, as were HOMA and AUC values. In MHT, NOx and cGMP significantly increased when moving from low to high Na+ intake, while nitrotyrosine mass and isoprostanes failed to show any change. On the contrary, in NMHT under low Na+ intake, urinary NOx levels were significantly higher than MHT under high Na+ intake, and failed to show any change under high Na intake; cGMP also failed to show any change when patients moved from low to high Na+ intake. Nitrotyrosine mass and isoprostanes, like to NOx, were significantly higher in NMHT under both low and high Na+ intake. CONCLUSIONS It is suggested that, in NMHT, a possible association between higher renin-angiotensin system activity, insulin resistance and endothelial dysfunction, showed for the first time in the same subjects, might result in systemic vascular and renal endothelial dysfunction, salt-sensitive hypertension and high cardiovascular risk.
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Abstract
BACKGROUND Endothelial dysfunction and subsequently impaired microvascular circulation are the leading mechanisms in the development of cardiac syndrome X (CSX). The study evaluated the plasma asymmetric dimethylarginine (ADMA) and L-arginine levels of the patients with CSX and the control group and aimed to determine any relationship between these parameters and epicardial coronary blood flow and myocardial tissue perfusion. METHODS The study group consisted of 32 patients (mean age: 52.6+/-9.4 years, 14 men) with typical exertional angina, positive exercise test, and normal coronary arteries diagnosed as CSX. Plasma ADMA, L-arginine levels, and L-arginine/ADMA ratio were compared with the values of the control group, which consisted of 17 age-matched and sex-matched individuals. Concentrations of L-arginine and ADMA were measured by high-performance liquid chromatography. In all the coronary territories, epicardial coronary flow was assessed by thrombolysis in myocardial infarction (TIMI) frame count (TFC) method, and tissue level perfusion, by myocardial blush grade (MBG) method. A MBG score less than 3 was considered an impaired myocardial perfusion, and a MBG score of '3' in all the coronary territories, a normal myocardial perfusion. RESULTS The plasma ADMA levels of the study group were higher than those of the control group (0.83+/-0.38 vs. 0.55+/-0.44 micromol/l, P=0.03), whereas plasma L-arginine levels were similar in both groups (70.25+/-21.89 vs. 76.09+/-18.22 micromol/l, P=0.36), resulting in a diminished L-arginine/ADMA ratio in the patients with CSX [82.3 (60.2-128.8) vs. 242.2 (76.7-386.4), P=0.003]. In CSX group, the patients with abnormal myocardial tissue perfusion had increased plasma ADMA levels compared with those with normal tissue perfusion (0.99+/-0.37 vs. 0.69+/-0.34 micromol/l, P=0.02), whereas plasma L-arginine levels were similar in both groups. No correlations were observed between TFC values and plasma ADMA, L-arginine levels, and L-arginine/ADMA ratio. Plasma ADMA levels, however, were negatively correlated with MBG scores (r=-0.349, P=0.014). CONCLUSION We have shown for the first time that in the patients with CSX, increased plasma ADMA levels might be associated with impaired myocardial tissue perfusion when assessed by MBG.
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Bishop MJ, Crow B, Norton D, Paliakov E, George J, Bralley JA. Direct analysis of un-derivatized asymmetric dimethylarginine (ADMA) and L-arginine from plasma using mixed-mode ion-exchange liquid chromatography-tandem mass spectrometry. J Chromatogr B Analyt Technol Biomed Life Sci 2007; 859:164-9. [PMID: 17931984 DOI: 10.1016/j.jchromb.2007.09.024] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2007] [Revised: 09/12/2007] [Accepted: 09/14/2007] [Indexed: 11/18/2022]
Abstract
A high-throughput analytical method was developed for the measurement of asymmetric dimethylarginine (ADMA) and L-arginine (ARG) from plasma using LC/MS/MS. The sample preparation was simple and only required microfiltration prior to analysis. ADMA and ARG were assayed using mixed-mode ion-exchange chromatography which allowed for the retention of the un-derivatized compounds. The need for chromatographic separation of ADMA from symmetric dimethylarginine (SDMA) was avoided by using an ADMA specific product ion. As a result, the analytical method only required a total run time of 2 min. The method was validated by linearity, with r2>or=0.995 for both compounds, and accuracy, with no more than 7% deviation from the theoretical value. The estimated limit of detection and limit of quantification were suitable for clinical evaluations. The mean values of plasma ADMA and ARG taken from healthy volunteers (n=15) were 0.66+/-0.12 and 87+/-35 microM, respectively; the mean molar ratio of ARG to ADMA was 142+/-81.
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Affiliation(s)
- Michael J Bishop
- Metametrix Clinical Laboratory, 3425 Corporate Way, Duluth, GA 30096, United States.
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Hemminki V, Laakso J, Kähönen M, Turjanmaa V, Uusitalo H, Lehtimäki T, Ruokonen I, Laaksonen R, Huhtala H, Päivä H. Plasma asymmetric dimethylarginine and retinal vessel diameters in middle-aged men. Metabolism 2007; 56:1305-10. [PMID: 17884437 DOI: 10.1016/j.metabol.2007.05.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2007] [Accepted: 05/25/2007] [Indexed: 11/21/2022]
Abstract
It has been suggested that asymmetric dimethylarginine (ADMA), an endogenous nitric oxide synthase inhibitor, is linked to hypertension and vascular reactivity. Retinal arteriolar narrowing has been observed to associate early with increased risk of hypertension. The objective of this study was to evaluate the role of ADMA as a biomarker for early vascular changes of retinal vessels and thus as a possible biomarker of hypertension risk. Thirty-five healthy white men aged 50.1 years (range, 45-55 years) were studied. Using digitized fundus photography, the following diameters of retinal arterioles and venules were measured 1 disc diameter from the optic disc edge: the mean arteriole width (MAW) and venule width (MVW), the sum of squares of widths of arterioles (SSWA) and venules (SSWV), and the central retinal artery equivalent (CRAE) and venous equivalent (CRVE). Arteriovenous ratio was determined using MAW/MVW, SSWA/SSWV, and CRAE/CRVE. Blood pressure was measured by 24-hour ambulatory recordings and also by resting measurements. Plasma ADMA was determined by a high-performance liquid chromatography tandem mass spectrometry. Plasma ADMA had a strong negative association with MAW, MVW, SSWA, SSWV, CRAE, and CRVE. Arteriovenous ratio measurements did not associate with plasma ADMA or with l-arginine to ADMA ratio, but arteriovenous ratios had a strong association with blood pressure. In a multivariate linear model, plasma ADMA concentration was the most significant predictor of arteriole and venule diameter measurements. These results suggest that plasma ADMA is associated with vascular phenomenon seen in early hypertension and that ADMA may be a potential biomarker candidate for development of hypertension.
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Affiliation(s)
- Virpi Hemminki
- Department of Clinical Physiology, Medical School, University of Tampere, 33014 Tampere, Finland
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17
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Jiang JL, Wang S, Li NS, Zhang XH, Deng HW, Li YJ. The inhibitory effect of simvastatin on the ADMA-induced inflammatory reaction is mediated by MAPK pathways in endothelial cells. Biochem Cell Biol 2007; 85:66-77. [PMID: 17464346 DOI: 10.1139/o06-146] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase, is emerging as a key contributor for endothelial dysfunction associated with inflammation. Statins can inhibit vascular inflammatory reaction and improve endothelial function. The aim of this study was to investigate in human endothelial cells the signaling pathways of ADMA-induced inflammatory reaction and potential inhibitory effects of simvastatin. Endothelial cells were cultured and used for all of the studies. Tumor necrosis factor-alpha(TNF-alpha) and soluble intercellular adhesion molecule-1 (sICAM-1) were determined by enzyme-linked immunosorbent assay. Nuclear factor-kappaB (NF-kappaB) was assayed by electrophoretic mobility shift assay. The activation of mitogen-activated protein kinases (MAPKs), including p38 MAPK and extracellular signal-related kinase (ERK(1/2)), were characterized by Western blot analysis. Treatment with ADMA (3-30 micromol/L) increased the concentration of sICAM-1 in a dose-dependent manner. ADMA (30 micromol/L) significantly enhanced the concentrations of TNF-alpha and sICAM-1, the activity of NF-kappaB and the phosphorylation of p38 MAPK and ERK(1/2). The increased secretion of TNF-alpha and sICAM-1 and the increased activity of NF-kappaB by ADMA were altered by SB203580 (5 micromol/L) or PD98059 (20 micromol/L), but not by LY294002 (20 micromol/L). Simvastatin (0.1, 0.5, or 2.5 micromol/L) markedly inhibited the elevated concentrations of TNF-alpha and sICAM-1, the activity of NF-kappaB, and the phosphorylation of p38 MAPK and ERK(1/2) induced by ADMA. Simvastatin inhibited ADMA-induced inflammatory reaction by p38 MAPK and ERK(1/2) pathways in cultured endothelial cells.
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Affiliation(s)
- Jun-Lin Jiang
- Department of Pharmacology, School of Pharmaceutical Sciences, Central South University, Xiang-Ya Road #110, Changsha 410078, China
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18
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Meinitzer A, Puchinger M, Winklhofer-Roob BM, Rock E, Ribalta J, Roob JM, Sundl I, Halwachs-Baumann G, März W. Reference values for plasma concentrations of asymmetrical dimethylarginine (ADMA) and other arginine metabolites in men after validation of a chromatographic method. Clin Chim Acta 2007; 384:141-8. [PMID: 17689511 DOI: 10.1016/j.cca.2007.07.006] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2007] [Revised: 07/03/2007] [Accepted: 07/03/2007] [Indexed: 11/30/2022]
Abstract
BACKGROUND Owing to the growing number of reports in the literature on ADMA as a possibly useful marker of endothelial health, its use in the clinical laboratory is of increasing interest. Age dependency and the small, but statistically significant differences between healthy subjects and disease groups are difficult to interpret. Additionally, levels of ADMA in comparable patient groups of different studies vary widely, even when similar methods have been used. METHODS After analytical evaluation of a chromatographic method according to international guidelines, we analysed asymmetrical (ADMA) and symmetrical dimethyl arginine (SDMA), homo-arginine and arginine in EDTA plasma of 292 healthy males aged 20 to 75 years (y) who had passed strict inclusion/exclusion criteria. For statistical analysis, 4 age groups were formed. Group differences were identified with the non-parametric Kruskal-Wallis test. RESULTS Calibration curves were linear throughout the selected ranges; the standard deviation for the regression line, recovery, imprecision, and accuracy results were all highly satisfactory. The reference ranges of ADMA for the 4 age groups are presented as age (mean+/-SD of age group, y); number of subjects; median, 2.5th-97.5th percentile: group <35 y: 26.7+/-4.0 y; n=78; 0.58, 0.43-0.69 micromol/L; group 35-49 y: 41.6+/-4.0 y; n=93; 0.59, 0.45-0.73 micromol/L; group 50-65 y: 57.5+/-4.2 y; n=82; 0.61, 0.46-0.78 micromol/L; and group >65 y: 69.6+/-3.3 y; n=39; 0.64, 0.54-0.79 micromol/L. CONCLUSIONS Only highly precise methods are able to detect small differences between groups. The application of an evaluated method to a well defined group of healthy subjects should provide a basis for comparison of ADMA concentrations in different patient populations of future studies.
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Affiliation(s)
- Andreas Meinitzer
- Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Austria.
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19
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Juonala M, Viikari JSA, Alfthan G, Marniemi J, Kähönen M, Taittonen L, Laitinen T, Raitakari OT. Brachial artery flow-mediated dilation and asymmetrical dimethylarginine in the cardiovascular risk in young Finns study. Circulation 2007; 116:1367-73. [PMID: 17724260 DOI: 10.1161/circulationaha.107.690016] [Citation(s) in RCA: 106] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
BACKGROUND Elevated asymmetrical dimethylarginine (ADMA) is a novel risk factor for atherosclerosis that may impair endothelial function by interfering with endothelial nitric oxide synthesis. To gain insight into the effects of ADMA on systemic endothelial function, we examined the association between ADMA and brachial artery flow-mediated dilation (FMD) in a large population of young adults. METHODS AND RESULTS Plasma ADMA and brachial FMD, as well as conventional cardiovascular risk factors, were measured in 2096 white adults aged 24 to 39 years. In univariate analysis, ADMA was inversely correlated with FMD (r=-0.07, P=0.003). The inverse association between ADMA and FMD remained significant in a multivariable regression model adjusted for age, sex, conventional cardiovascular risk factors, estimated glomerular filtration rate, and brachial artery baseline diameter (beta+/-SE -1.56+/-0.62%, P=0.01). CONCLUSIONS We conclude that elevated plasma ADMA concentrations are associated with decreased brachial FMD responses in healthy adults. These data provide evidence at the population level that ADMA levels are associated with endothelial function.
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Affiliation(s)
- Markus Juonala
- Department of Medicine, University of Turku, 20521 Turku, Finland
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20
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Zsuga J, Torok J, Magyar MT, Valikovics A, Gesztelyi R, Kéki S, Csiba L, Zsuga M, Bereczki D. Serum asymmetric dimethylarginine negatively correlates with intima-media thickness in early-onset atherosclerosis. Cerebrovasc Dis 2007; 23:388-94. [PMID: 17406107 DOI: 10.1159/000101461] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2006] [Accepted: 11/19/2006] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Asymmetric dimethylarginine (ADMA) assumes a significant role in atherosclerosis by inhibiting the endothelial nitric oxide synthase (eNOS). Moreover, ADMA inhibits the inducible NOS (iNOS), the isoform that triggers atherosclerosis via peroxynitrite formation. Therefore, we investigated whether ADMA is a risk or protective factor in the atherosclerotic process. Intima-media thickness (IMT) of the common carotid artery, a surrogate for vascular diseases, was chosen as the outcome variable of interest. METHODS Sixty patients younger than 55 years having at least 30% stenosis of the internal carotid artery and 30 age- and gender-matched controls were recruited at a community-based neurosonological laboratory. We investigated relatively young patients to circumvent the confounding effect age has in the development of atherosclerosis. RESULTS The IMT showed a negative correlation with ADMA upon analysis of the pooled data (Spearman correlation coefficient -0.300, p = 0.0041) and the atherosclerotic stratum (Spearman correlation coefficient -0.323, p = 0.012). A multiple linear regression model containing all determinant factors of IMT previously identified by simple regression was used to further quantify the relationship between IMT and ADMA. The negative association between IMT and ADMA remained statistically significant (beta: -0.510, CI: -0.894, -0.127; p = 0.010), furthermore it was even stronger in the atherosclerotic stratum (beta: -0.67, CI: -1.16, -0.18; p = 0.008). CONCLUSIONS A minimal increase in ADMA concentration may be protective by inhibiting iNOS but not eNOS in states where iNOS is induced, e.g. inflammation accompanying atherosclerosis.
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Affiliation(s)
- Judit Zsuga
- Department of Neurology, University of Debrecen, Debrecen, Hungary.
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21
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Horowitz JD, Heresztyn T. An overview of plasma concentrations of asymmetric dimethylarginine (ADMA) in health and disease and in clinical studies: methodological considerations. J Chromatogr B Analyt Technol Biomed Life Sci 2006; 851:42-50. [PMID: 17045556 DOI: 10.1016/j.jchromb.2006.09.023] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2006] [Revised: 09/11/2006] [Accepted: 09/12/2006] [Indexed: 01/17/2023]
Abstract
Recent studies among patients including those with known coronary disease demonstrate that small elevations in asymmetric dimethylarginine (ADMA) concentrations in plasma are predictive of adverse outcomes. The precision of current methodologies for quantitation of ADMA such as HPLC, MS and ELISA is discussed with respect to many reports which appear to over-estimate ADMA levels and quote broad concentration ranges. While plasma ADMA concentrations tend to increase with age, the mean for a healthy population is between 0.4 and 0.6 microM. ADMA levels may fluctuate in normal subjects, and this needs to be considered in light of the relatively small differences in ADMA concentration between healthy normal subjects and patients.
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Affiliation(s)
- John D Horowitz
- Cardiology Unit, Queen Elizabeth Hospital, University of Adelaide, 28 Woodville Road, Woodville South, SA, Australia.
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22
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Päivä H, Laakso J, Ruokonen I, Luomala M, Saarela M, Solakivi T, Metso S, Nikkilä M, Wuolijoki E, Laaksonen R, Lehtimäki T. Plasma asymmetric dimethylarginine (ADMA), nitrate and the indices of low-density lipoprotein oxidation. Clin Chim Acta 2006; 371:97-101. [DOI: 10.1016/j.cca.2006.02.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2005] [Revised: 02/21/2006] [Accepted: 02/21/2006] [Indexed: 11/29/2022]
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23
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Päivä H, Laakso J, Kähönen M, Turjanmaa V, Kööbi T, Majahalme S, Lehtimäki T, Ruokonen I, Laaksonen R. Asymmetric dimethylarginine and hemodynamic regulation in middle-aged men. Metabolism 2006; 55:771-7. [PMID: 16713437 DOI: 10.1016/j.metabol.2006.01.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2005] [Accepted: 01/08/2006] [Indexed: 11/22/2022]
Abstract
The goal of this study was to evaluate the role of asymmetric dimethylarginine (ADMA) in the regulation of hemodynamic functions in hypertensive men. It has been suggested that ADMA, as an endogenous nitric oxide synthase inhibitor, is linked to hypertension and vascular reactivity. Sixty-seven men aged 51.1 years (range, 45-55 years) were studied. Plasma ADMA and symmetric dimethylarginine were determined by high-performance liquid chromatography-tandem mass spectrometry. Blood pressure (BP) was measured by 24-hour ambulatory recordings and casual measurements. Hemodynamic regulation was assessed by noninvasive methods. The nitric oxide production was estimated based on plasma nitrate (NO(3)(-)) determination. Results showed that plasma arginine derivatives or l-arginine/ADMA ratio was not associated with BP values observed during 24-hour monitoring or in casual measurements. Systemic vascular resistance, pulse wave velocity, or cardiac output was not associated with plasma ADMA or plasma NO(3)(-) levels. No association was found between plasma ADMA and NO(3)(-) either. Interestingly, subjects on antihypertensive treatment had lower plasma ADMA concentrations than nontreated subjects (0.30+/-0.08 and 0.36+/-0.11 micromol/L, respectively, P=.04) despite higher BP values. In conclusion, these results suggest that plasma ADMA does not have a determinative role in the regulation of hemodynamic functions in Finnish middle-aged men.
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Affiliation(s)
- Hannu Päivä
- Department of Internal Medicine, Tampere University Hospital, 33521 Tampere, Finland.
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24
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Abstract
The endogenous inhibitor of the nitric oxide synthase, asymmetric dimethylarginine (ADMA), by reducing nitric oxide (NO) availability, may trigger pro-atherogenic effects. A high plasma concentration of this substance has been associated to intima-media thickening, left ventricular hypertrophy and all-cause and cardiovascular mortality in patients with end-stage renal disease, and to coronary events in males in the general population. Recent studies show that ADMA predicts renal disease progression and death in patients with moderate to severe renal insufficiency. ADMA may be at the crossroad of the atherosclerosis process and may represent an important factor in the high risk associated with renal insufficiency.
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Affiliation(s)
- Carmine Zoccali
- Nephrology, Hypertension and Renal Transplantation, CNR-IBIM Clinical Epidemiology of Renal Diseases and Hypertension, Ospedali Riuniti, Reggio Cal, Italy.
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25
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Wierzbicki AS, Solomon H, Lumb PJ, Lyttle K, Lambert-Hammill M, Jackson G. Asymmetric dimethyl arginine levels correlate with cardiovascular risk factors in patients with erectile dysfunction. Atherosclerosis 2006; 185:421-5. [PMID: 16046217 DOI: 10.1016/j.atherosclerosis.2005.06.025] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2005] [Revised: 06/15/2005] [Accepted: 06/21/2005] [Indexed: 11/15/2022]
Abstract
BACKGROUND Erectile dysfunction is related to penile arterial endothelial nitric oxide production. Asymmetric dimethylarginine (ADMA) and E-selectin are often considered plasma markers of endothelial function. OBJECTIVE This study investigated the relationship between these plasma markers and cardiovascular risk factors in patients with erectile dysfunction. METHODS AND RESULTS Cardiovascular risk factors, ADMA and E-selectin were assessed in 45 patients with erectile dysfunction. Plasma markers showed associations with baseline risk factors. E-selectin levels showed an inverse relationship with age (p = 0.005) and statin therapy (p = 0.03) and a weak association with concomitant beta-blocker therapy (p = 0.05). Compared to these relatively weak associations with cardiovascular risk factors, ADMA levels showed strong associations with pulse pressure (p < 0.001), lack of smoking (p = 0.002) and lipoprotein (a) (p = 0.004) concentrations and weak associations with LDL-cholesterol (p = 0.02), and C-reactive protein levels (p = 0.04). ADMA levels correlated with E-selectin (partial r = 0.76; p < 0.001) after adjustment for lipoprotein (a), pulse pressure and smoking. No change in E-selectin or ADMA levels was seen after 70 days therapy with sildenafil and no relationship was found between either plasma marker and the acute pulse wave response to a single challenge dose of sildenafil. CONCLUSION ADMA levels correlate at baseline with some cardiovascular risk factors including inflammatory markers and lipoprotein (a) in patients with erectile dysfunction.
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Affiliation(s)
- Anthony S Wierzbicki
- Department of Chemical Pathology, St. Thomas' Hospital Lambeth Palace Road, London SE1 7EH, UK.
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26
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Langheinrich AC, Bohle RM. Atherosclerosis: humoral and cellular factors of inflammation. Virchows Arch 2005; 446:101-11. [PMID: 15688168 DOI: 10.1007/s00428-004-1180-4] [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: 09/11/2004] [Accepted: 11/17/2004] [Indexed: 10/25/2022]
Abstract
In the past decade, atherosclerosis has come to be recognized as active and inflammatory rather than simply a passive process of lipid infiltration or a reparative process after endothelial injury. In general, atherosclerosis can be considered as an intramural chronic inflammation resulting from interactions between modified lipoproteins, monocyte-derived macrophages, lymphocytes, and the normal cellular elements of the arterial wall. The process of inflammation occurs in response to functional and structural injury through a variety of known and unknown stimuli and is active over years and decades. Here, we review recent experimental and human studies of inflammatory mechanisms underlying the pathogenesis of atherosclerosis.
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Affiliation(s)
- A C Langheinrich
- Department of Diagnostic Radiology, Universitätsklinikum, Klinikstr. 36, 35392, Giessen, Germany
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27
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Fliser D. Asymmetric dimethylarginine (ADMA): the silent transition from an 'uraemic toxin' to a global cardiovascular risk molecule. Eur J Clin Invest 2005; 35:71-9. [PMID: 15667575 DOI: 10.1111/j.1365-2362.2005.01457.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Endothelial dysfunction as a result of reduced bioavailability of nitric oxide (NO) plays a central role in the process of atherosclerotic vascular disease. In endothelial cells NO is synthesized from the amino acid l-arginine by the action of the NO synthase (NOS), which can be blocked by endogenous inhibitors such as asymmetric dimethylarginine (ADMA). Acute systemic administration of ADMA to healthy subjects significantly reduces NO generation, and causes an increase in systemic vascular resistance and blood pressure. Increased plasma ADMA levels as a result of reduced renal excretion have been associated with atherosclerotic complications in patients with terminal renal failure. However, a significant relationship between ADMA and traditional cardiovascular risk factors such as advanced age, high blood pressure and serum LDL-cholesterol, has been documented even in individuals without manifest renal dysfunction. As a consequence, the metabolism of ADMA by the enzyme dimethylarginine dimethylaminohydrolase (DDAH) has come into the focus of cardiovascular research. It has been proposed that dysregulation of DDAH with consecutive increase in plasma ADMA concentration and chronic NOS inhibition is a common pathophysiological pathway in numerous clinical conditions. Thus, ADMA has emerged as a potential mediator of atherosclerotic complications in patients with coronary heart disease, peripheral vascular disease, stroke, etc., being the culprit and not only an innocent biochemical marker of the atherosclerotic disease process.
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Affiliation(s)
- D Fliser
- Division Nephrol, Department of Int. Medicine, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany.
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28
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Heresztyn T, Worthley MI, Horowitz JD. Determination of l-arginine and NG, NG - and NG, NG' -dimethyl-L-arginine in plasma by liquid chromatography as AccQ-Fluor fluorescent derivatives. J Chromatogr B Analyt Technol Biomed Life Sci 2005; 805:325-9. [PMID: 15135108 DOI: 10.1016/j.jchromb.2004.03.020] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2003] [Revised: 03/12/2004] [Accepted: 03/12/2004] [Indexed: 11/27/2022]
Abstract
A new HPLC assay for the detection of L-arginine, NG, NG-dimethyl-L-arginine (ADMA) and NG, NG' -dimethyl-L-arginine (SDMA) in plasma using the derivatisation reagent AccQ-Fluor (6-aminoquinolyl-N-hydroxysuccinimidyl carbamate) is described. The fluorescent derivatives produced are extremely stable enabling routine processing of large numbers of samples. Arginine and its metabolites are extracted from plasma on strong cation exchange (SCX) cartridges with NG-monomethyl-L-arginine (NMMA) as internal standard, derivatised and separated on a C18 column with acetonitrile in 0.1M sodium acetate buffer pH 6. Separation of the stereoisomers ADMA and SDMA was excellent and improvements to the solid phase extraction (SPE) procedure enabled good recovery (>80%) of arginine, ADMA and SDMA. The utility of the method is exemplified by comparison of plasma concentrations of ADMA, SDMA and arginine in healthy volunteers and diabetic/ischaemic patients.
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29
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Valkonen VP, Laaksonen R. Asymmetric dimethylarginine (ADMA) and acute vascular events. Clin Chim Acta 2004; 348:9-17. [PMID: 15369730 DOI: 10.1016/j.cccn.2004.05.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2004] [Revised: 05/12/2004] [Accepted: 05/14/2004] [Indexed: 11/25/2022]
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30
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Päivä H, Lehtimäki T, Laakso J, Ruokonen I, Tervonen R, Metso S, Nikkilä M, Wuolijoki E, Laaksonen R. Dietary composition as a determinant of plasma asymmetric dimethylarginine in subjects with mild hypercholesterolemia. Metabolism 2004; 53:1072-5. [PMID: 15281021 DOI: 10.1016/j.metabol.2003.12.028] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Asymmetric dimethylarginine (ADMA) is an endogenous nitric oxide synthase inhibitor that participates in the regulation of vasodilatory function and is also linked to hypertension, whereas its stereoisomere, symmetric dimethylarginine (SDMA), is biologically inactive. Dietary components influence vascular functions and a high-fat meal seems to increase postprandial plasma ADMA levels. However, it has not been published whether diet influences plasma ADMA levels. In this study, we investigated the impact of diet on plasma ADMA and SDMA levels. Thirty-four mildly hypercholesterolemic, otherwise healthy women (n = 14) and men (n = 20) with a mean age of 46.2 years (range, 35 to 62 years) participated in the study. The subjects were examined twice at intervals of 2 months. Seven-day food records were used to analyze diet and alcohol intake. ADMA was measured by using high-performance liquid chromatography (HPLC)-tandem mass spectrometry. In a multivariate analysis (R2 = 0.20, P < .002), low amount of energy received from carbohydrates (r = -0.31, P = .009) and high plasma triglycerides (r = 0.30, P = .01) were predictors of high ADMA plasma levels. Alcohol drinkers had higher plasma ADMA concentrations than abstainers (0.50 +/- 0.13 v 0.42 +/- 0.11 micromol/L, P = .04). Plasma ADMA correlated with systolic (r = 0.60, P = .005) and diastolic blood pressure (r = 0.53, P = .02) in abstainers but not in alcohol drinkers. Plasma SDMA was not associated with any dietary components or with blood pressure. In conclusion, a high amount of dietary carbohydrates is strongly associated with low levels of plasma ADMA. Concentration of ADMA in plasma seems to be higher in alcohol drinkers than in abstainers.
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Affiliation(s)
- Hannu Päivä
- Department of Internal Medicine, Tampere University Hospital, Finland
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31
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Smirnova IV, Sawamura T, Goligorsky MS. Upregulation of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) in endothelial cells by nitric oxide deficiency. Am J Physiol Renal Physiol 2004; 287:F25-32. [PMID: 15010359 DOI: 10.1152/ajprenal.00449.2003] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Endothelial cell dysfunction (ECD) is emerging as a common denominator for diverse cardiovascular abnormalities associated with inhibition of endothelial nitric oxide (NO) synthase (eNOS). Elevated levels of asymmetric dimethylarginine (ADMA), a potent eNOS inhibitor, are common in renal failure and may contribute to ECD. Through DNA microarray screening of genes modulated in human umbilical vein endothelial cells (HUVEC) by NG-nitro-l-arginine methyl ester (l-NAME), we found a 1.8-fold increase in low-density lipoprotein receptor-1 (LOX-1) expression. LOX-1 is a major endothelial receptor for oxidized low-density lipoproteins (OxLDL) and is assumed to play a role in the initiation and progression of atherosclerosis. Here, we confirmed the upregulation of LOX-1 mRNA and protein level by quantitative RT-PCR and Western blot analysis. Increased expression of LOX-1 was associated with the accumulation of DiI-labeled OxLDL (DiI-OxLDL) in ADMA- and l-NAME-pretreated HUVEC. To evaluate the contribution of LOX-1 in ADMA-induced accumulation of OxLDL by HUVEC, we used the competitive receptor inhibitor, soluble LOX-1. Treatment of HUVEC with soluble LOX-1 was associated with an approximately two- to threefold inhibition of DiI-OxLDL uptake in l-NAME- or ADMA-treated HUVEC. In conclusion, ADMA- or l-NAME-induced NO deficiency leads to the increased expression of LOX-1 mRNA and protein in HUVEC, which in turn results in the accumulation of OxLDL. Competition with LOX-1-soluble extracellular domain reduces OxLDL accumulation. In summary, elevated ADMA levels, i.e., in patients with renal failure, may be responsible for endothelial accumulation of OxLDL via upregulated LOX-1 receptor, thus contributing to endothelial lipidosis and dysfunction.
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Affiliation(s)
- I V Smirnova
- Department of Medicine, Renal Research Institute, New York Medical College, Valhalla, NY 10595, USA
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32
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Fleck C, Schweitzer F, Karge E, Busch M, Stein G. Serum concentrations of asymmetric (ADMA) and symmetric (SDMA) dimethylarginine in patients with chronic kidney diseases. Clin Chim Acta 2004; 336:1-12. [PMID: 14500028 DOI: 10.1016/s0009-8981(03)00338-3] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
BACKGROUND NO synthesis is inhibited by the dimethylarginine (DMA) ADMA, which accumulates, similar to SDMA, in the plasma of patients suffering from chronic renal failure (CRF). ADMA and possibly SDMA contribute to hypertension and atherosclerosis in patients with chronic renal disease: ADMA inhibits directly eNOS, whereas SDMA competes with the NO precursor arginine for uptake into the cells. METHODS In 26 control persons and 221 patients with kidney diseases of different stage as were CRF, end stage renal disease (ESRD), and patients after renal transplantation (RT), the plasma concentrations of ADMA (c(ADMA)), SDMA (c(SDMA)) and 20 endogenous amino acids (AA) were measured by HPLC and correlated to blood pressure, cardiac events, endothelial dysfunction, and diabetes mellitus. RESULTS Both ADMA (1.04+/-0.04 vs. 0.66+/-0.04 microM) and SDMA (2.69+/-0.12 vs. 0.49+/-0.03 microM) were significantly (p<0.001) elevated in all patients compared to healthy controls, whereas arginine concentration (51.4+/-2.3 vs. 76.0+/-5.2 microM) was decreased in dependence on the degree of kidney disease. In RT patients, SDMA levels were significantly decreased, but c(ADMA) remained enhanced. A strong correlation was found between SDMA and both serum urea and creatinine in CRF and RT patients. A linear correlation was found between ADMA and cholesterol concentrations in RT patients. Hypertension in CRF was accompanied by a further increase in the concentration of DMAs. There was no relation between DMAs and the occurrence of peripheral arterial occlusive disease or cerebrovascular diseases. In patients with cardiac diseases, c(SDMA) was additionally increased only in the CRF group. CONCLUSIONS In patients with chronic kidney disease, c(ADMA) and c(SDMA) are significantly increased but cardiovascular diseases are evidently not correlated to changes in DMA concentrations in this group of patients.
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Affiliation(s)
- Christian Fleck
- Institut für Pharmakologie und Toxikologie, Klinikum der Friedrich-Schiller-Universität Jena, D-07740, Jena, Germany.
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Janatuinen T, Laakso J, Laaksonen R, Vesalainen R, Nuutila P, Lehtimäki T, Raitakari OT, Knuuti J. Plasma asymmetric dimethylarginine modifies the effect of pravastatin on myocardial blood flow in young adults. Vasc Med 2004; 8:185-9. [PMID: 14989559 DOI: 10.1191/1358863x03vm490oa] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Elevated plasma levels of the endogenous nitric oxide synthase inhibitor asymmetric dimethylarginine (ADMA) are related to decreased myocardial vasodilatory capacity and increased risk of acute coronary events. As statin treatment is known to increase nitric oxide bioavailability and enhance myocardial function, we tested whether ADMA concentration modifies the effect of pravastatin on myocardial blood flow in young adults with mild hypercholesterolemia. Fifty-one men (35 +/- 4 years) were randomly assigned to receive either pravastatin (40 mg/day) or placebo for 6 months. Myocardial blood flow was measured at rest and during adenosine-induced hyperemia using positron emission tomography and oxygen-15-labeled water at baseline and after treatment. Plasma ADMA levels were assessed with high performance liquid chromatography. Low baseline plasma ADMA concentration (< median) predicted a significant improvement of adenosine-induced blood flow after statin intervention (baseline to follow-up change +35%, p = 0.004), whereas high baseline ADMA (> or = median) was associated with no increase in adenosine-induced flow.
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Valkonen VP, Laakso J, Päivä H, Lehtimäki T, Lakka TA, Isomustajärvi M, Ruokonen I, Salonen JT, Laaksonen R. Asymmetrical dimethylarginine (ADMA) and risk of acute coronary events. Does statin treatment influence plasma ADMA levels? ATHEROSCLEROSIS SUPP 2004; 4:19-22. [PMID: 14664898 DOI: 10.1016/s1567-5688(03)00029-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The purpose of this study was to evaluate the hypothesis that high serum levels of ADMA, an indicator of endothelial dysfunction, are associated with an elevated risk of acute coronary events in middle-aged men. To test the hypothesis that lipid lowering medication with statins lowers circulating ADMA levels, we also investigated the effect of simvastatin and atorvastatin treatment on plasma ADMA concentration. In a prospective nested case-control study in 150 middle-aged non-smoking men from Eastern Finland, those who were in the highest quartile for serum ADMA (>0.62 micromol/l) had a 3.9-fold (95% CI: 1.25-12.3, P=0.02) increase in risk of acute coronary events compared with other quartiles. In an 8-week randomised double-blind placebo-controlled trial, plasma ADMA concentrations remained unchanged in simvastatin 80 mg/day (n=16), atorvastatin 40 mg/day (n=16) and placebo (n=16) groups over the study period. Our findings indicate that high serum levels of ADMA, a potential marker for endothelial dysfunction, may increase the risk of acute coronary syndromes. However, aggressive treatment with either simvastatin or atorvastatin did not reduce plasma ADMA levels.
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John S, Schmieder RE. Potential mechanisms of impaired endothelial function in arterial hypertension and hypercholesterolemia. Curr Hypertens Rep 2003; 5:199-207. [PMID: 12724051 DOI: 10.1007/s11906-003-0021-1] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
This review focuses on the role of impaired endothelial function for the development of atherosclerosis in human arterial hypertension and hypercholesterolemia in vivo. Potential mechanisms underlying impaired endothelial function and decreased bioavailability of nitric oxide under these clinical conditions are discussed. It further addresses therapeutic strategies aimed at improving the bioavailability of nitric oxide in these patients. The overall conclusion is that the bioavailability of nitric oxide is probably impaired, not by a single defect, but by various mechanisms affecting nitric oxide synthesis as well as nitric oxide breakdown. In both diseases increased superoxide anion production and oxidative stress represent a major mechanism. Decreased bioavailability of nitric oxide not only impairs endothelium-dependent vasodilation, but also activates other mechanisms that play an important role in the pathogenesis of atherosclerosis. Thus, therapeutic strategies should aim to restore bioavailability of nitric oxide, which has been demonstrated for lipid-lowering therapy in hypercholesterolemia and blood pressure control in hypertension. In addition, antioxidative strategies will represent a major therapeutic tool against atherosclerotic diseases in the future. Statins and blockers of the renin-angiotensin system seem to have such antioxidative effects independent from their effects on lipid profiles or blood pressure control.
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Affiliation(s)
- Stefan John
- Department of Medicine IV, University of Erlangen-Nürnberg,Klinikum Nürnberg-Süd, Breslauerstr 201, 90471 Nürnberg, Germany
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Päivä H, Lehtimäki T, Laakso J, Ruokonen I, Rantalaiho V, Wirta O, Pasternack A, Laaksonen R. Plasma concentrations of asymmetric-dimethyl-arginine in type 2 diabetes associate with glycemic control and glomerular filtration rate but not with risk factors of vasculopathy. Metabolism 2003; 52:303-7. [PMID: 12647267 DOI: 10.1053/meta.2003.50048] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide synthase (NOS). Increased plasma levels of ADMA may indicate endothelial dysfunction and increased risk of angiopathy. The relation of ADMA to diabetes, glycemic control, and renal function, especially early diabetic hyperfiltration, remains unknown. We tried to evaluate whether there is an association between ADMA and glycosylated hemoglobin (GHbA(1c)) on the one hand and glomerular filtration rate (GFR) on the other hand in diabetic subjects with normal or slightly increased GFR. We also studied whether plasma ADMA is associated with some risk factors of vasculopathy (hypercholesterolemia and hypertension). The study subjects consisted of 86 patients with type 2 diabetes and 65 control subjects. Plasma ADMA levels were measured by high-pressure liquid chromatography as o-pthalaldehyde (OPA) derivatives and GFR was determined by the plasma clearance of chromium 51-EDTA. The diabetic patients had lower plasma ADMA levels than the nondiabetic control subjects (0.29 +/- 0.15 v 0.34 +/- 0.16 micromol/L, P <.03). In the diabetic subjects, plasma ADMA concentrations were inversely correlated with GHbA(1c) (R = -0.28, P =.01). In a multivariate linear model, significant predictors of ADMA were GFR (R = -0.32, P =.008) in diabetic subjects and GHbA(1c) (R = -0.19, P =.03) and GFR (R = -0.19, P =.02) in all subjects. Plasma ADMA was not associated with risk factors of vasculopathy. We conclude that diabetic patients with a normal or slightly increased GFR have lower circulating ADMA concentrations than nondiabetic control subjects. In type 2 diabetic patients high GFR and poor glycemic control were related to low plasma ADMA concentrations.
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Affiliation(s)
- Hannu Päivä
- Department of Internal Medicine, Tampere University Hospital, Tampere, Finland
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