scholarly journals Pharmacotherapies and their influence on asymmetric dimethylargine (ADMA)

2005 ◽  
Vol 10 (1_suppl) ◽  
pp. S49-S57 ◽  
Author(s):  
Renke Maas

Elevated plasma concentrations of the endogenous nitric oxide synthase inhibitor asymmetric dimethylarginine (ADMA) are found in various clinical settings, including renal failure, coronary heart disease, hypertension, diabetes and pre eclampsia. In healthy people acute infusion of ADMA promotes vascular dysfunc tion, and in mice chronic infusion of ADMA promotes progression of atherosclerosis. Thus, ADMA may not only be a marker but also an active player in cardiovascular disease, which makes it a potential target for therapeutic interventions. This review provides a summary and critical discussion of the presently available data concern ing the effects on plasma ADMA levels of cardiovascular drugs, hypoglycemic agents, hormone replacement therapy, antioxidants, and vitamin supplementation. We assess the evidence that the beneficial effects of drug therapies on vascular func tion can be attributed to modification of ADMA levels. To develop more specific ADMA-lowering therapies, mechanisms leading to elevation of plasma ADMA con centrations in cardiovascular disease need to be better understood. ADMA is formed endogenously by degradation of proteins containing arginine residues that have been methylated by S-adenosylmethionine-dependent methyltransferases (PRMTs). There are two major routes of elimination: renal excretion and enzymatic degrada tion by the dimethylarginine dimethylaminohydrolases (DDAH-1 and -2). Oxidative stress causing upregulation of PRMT expression and/or attenuation of DDAH activity has been suggested as a mechanism and possible drug target in clinical conditions associated with elevation of ADMA. As impairment of DDAH activity or capacity is associated with substantial increases in plasma ADMA concentrations, DDAH is likely to emerge as a prime target for specific therapeutic interventions.

2005 ◽  
Vol 10 (2_suppl) ◽  
pp. S49-S57 ◽  
Author(s):  
Renke Maas

Elevated plasma concentrations of the endogenous nitric oxide synthase inhibitor asymmetric dimethylarginine (ADMA) are found in various clinical settings, including renal failure, coronary heart disease, hypertension, diabetes and preeclampsia. In healthy people acute infusion of ADMA promotes vascular dysfunction, and in mice chronic infusion of ADMA promotes progression of atherosclerosis. Thus, ADMA may not only be a marker but also an active player in cardiovascular disease, which makes it a potential target for therapeutic interventions. This review provides a summary and critical discussion of the presently available data concerning the effects on plasma ADMA levels of cardiovascular drugs, hypoglycemic agents, hormone replacement therapy, antioxidants, and vitamin supplementation. We assess the evidence that the beneficial effects of drug therapies on vascular function can be attributed to modification of ADMA levels. To develop more specific ADMA-lowering therapies, mechanisms leading to elevation of plasma ADMA concentrations in cardiovascular disease need to be better understood. ADMA is formed endogenously by degradation of proteins containing arginine residues that have been methylated by S-adenosylmethionine-dependent methyltransferases (PRMTs). There are two major routes of elimination: renal excretion and enzymatic degradation by the dimethylarginine dimethylaminohydrolases (DDAH-1 and -2). Oxidative stress causing upregulation of PRMT expression and/or attenuation of DDAH activity has been suggested as a mechanism and possible drug target in clinical conditions associated with elevation of ADMA. As impairment of DDAH activity or capacity is associated with substantial increases in plasma ADMA concentrations, DDAH is likely to emerge as a prime target for specific therapeutic interventions.


2012 ◽  
Vol 303 (1) ◽  
pp. F149-F156 ◽  
Author(s):  
Rianne A. Ronden ◽  
Alfons J. H. M. Houben ◽  
Tom Teerlink ◽  
Jaap A. Bakker ◽  
Jörgen Bierau ◽  
...  

Plasma concentrations of the nitric oxide synthase inhibitor asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA) increase already in the early stages of renal insufficiency. There is no agreement as to whether reduced renal plasma clearance (RPCL) contributes to this increase. Therefore, we investigated the relationship between estimated glomerular filtration rate (eGFR), RPCL, and plasma ADMA and SDMA in essential hypertensive patients with mild to moderate renal insufficiency. In 171 patients who underwent renal angiography, we drew blood samples from the aorta and both renal veins and measured mean renal blood flow (MRBF) using the 133Xe washout technique. RPCL was calculated using arteriovenous concentration differences and MRBF. After correction for potential confounders, reduced eGFR was associated with higher plasma ADMA and SDMA [standardized regression coefficient (β) = −0.22 (95% confidence intervals: −0.41, −0.04) and β = −0.66 (95% confidence intervals: −0.83, −0.49), respectively]. However, eGFR was not independently associated with RPCL of ADMA. Moreover, reduced RPCL of ADMA was not associated with higher plasma ADMA. Contrary to ADMA, reduced eGFR was indeed associated with lower RPCL of SDMA [β = 0.21 (95% confidence intervals: 0.02, 0.40)] . In conclusion, our findings indicate that RPCL of ADMA is independent of renal function in hypertensive patients with mild to moderate renal insufficiency. Unlike the case for SDMA, reduced RPCL of ADMA is of minor importance for the increase in plasma ADMA in these patients, which indicates that increased plasma ADMA in this population is not a direct consequence of the kidneys failing as a plasma ADMA-regulating organ.


Author(s):  
Coen van Guldener ◽  
Prabath W.B. Nanayakkara ◽  
Coen D.A. Stehouwer

AbstractAsymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase, is formed by methylation of arginine residues in proteins and released after proteolysis. In this reaction, S-adenosylmethionine is methyldonor and S-adenosylhomocysteine the demethylated product. ADMA and homocysteine are thus biochemically linked. Both plasma homocysteine and ADMA concentrations are increased in patients with renal dysfunction, probably as a result of an impairment in their metabolic, but not urinary, clearance. Hyperhomocysteinemia has been associated with an increased risk of cardiovascular disease in end-stage renal disease, especially in patients without malnutrition and inflammation. Also, plasma ADMA levels have been associated with cardiovascular disease in renal failure patients. Both homocysteine and ADMA are thought to mediate their adverse vascular effects by impairing endothelial, nitric oxide-dependent function resulting in decreased vasodilatation, increased smooth muscle cell proliferation, platelet dysfunction and increased monocyte adhesion. At the same time, it has been shown that the correlation between plasma ADMA and homocysteine is weak and that, in renal patients, the association of plasma ADMA carotid intima-media thickness, cardiovascular events and overall mortality is independent of homocysteine. This indicates that the negative vascular effects of ADMA and homocysteine have a different etiology. Treatment with folic acid substantially lowers homocysteine, but not ADMA concentration. So far, homocysteine-lowering therapy has not been very successful in decreasing cardiovascular disease. In patients with renal failure, ADMA reduction may be an interesting new goal in the prevention of cardiovascular disease.Clin Chem Lab Med 2007;45:1683–7.


Author(s):  
John R Burnett ◽  
Samuel D Vasikaran

Atherosclerotic heart disease and osteoporosis are both diseases of old age. Evidence is accumulating for a link between vascular and bone disease. Calcification is a common feature of atherosclerotic plaques, and osteoporosis is associated with both atherosclerosis and vascular calcification. However, the relationship of vascular calcification to the pathogenesis of atherosclerosis remains incompletely understood. Hormone replacement therapy has beneficial effects in the prevention of both atherosclerosis and osteoporosis. Bisphosphonates inhibit bone resorption and are used in the treatment of osteoporosis, whereas the statins inhibit cholesterol biosynthesis and are used for the treatment of atherosclerosis. We have reviewed recent advances in the knowledge of the actions of bisphosphonates and statins at the cellular, molecular and end-organ levels in order to examine the relationship between cardiovascular disease and osteoporosis and to explore the link between lipids and bones. These studies suggest that the mechanism of actions of these two classes of drugs at the cellular level may not be mutually exclusive. There are some early clinical data to complement these findings, suggesting that statins increase bone density and bisphosphonates may have a beneficial effect in vivo on plasma lipid levels and on the atherosclerotic process. Properly designed prospective studies that examine the effect of statins on bone density and fractures, as well as the effects of bisphosphonates on lipid profiles, atherosclerotic progression and cardiovascular morbidity and mortality are needed to define clearly the clinical effects and potential new roles for these agents.


BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Úna McMenamin ◽  
Blánaid Hicks ◽  
Carmel Hughes ◽  
Peter Murchie ◽  
Julia Hippisley-Cox ◽  
...  

Abstract Background Hormone replacement therapy (HRT) is widely used and has proven benefits for women with menopausal symptoms. An increasing number of women with cancer experience menopausal symptoms but the safety of HRT use in women with cancer is unclear. There are particular concerns that HRT could accelerate cancer progression in women with cancer, and also that HRT could increase the risk of cardiovascular disease in such women. Therefore, our primary aim is to determine whether HRT use alters the risk of cancer-specific mortality in women with a range of common cancers. Our secondary objectives are to investigate whether HRT alters the risk of second cancers, cardiovascular disease, venous thromboembolism and all-cause mortality. Methods The study will utilise independent population-based data from Wales using the SAIL databank and Scotland based upon the national Prescribing Information System. The study will include women newly diagnosed with common cancers from 2000 to 2016, identified from cancer registries. Women with breast cancers will be excluded. HRT will be ascertained using electronic prescribing in Wales or dispensing records in Scotland. The primary outcome will be time to cancer-specific mortality from national mortality records. Time-dependent cox regression models will be used to calculate hazard ratios (HR) and 95% confidence intervals (95% CIs) for cancer specific death in HRT users compared with non-users after cancer diagnosis after adjusting for relevant confounders, stratified by cancer site. Analysis will be repeated investigating the impact of HRT use immediately before cancer diagnosis. Secondary analyses will be conducted on the risk of second cancers, cardiovascular disease, venous thromboembolism and all-cause mortality. Analyses will be conducted within each cohort and pooled across cohorts. Discussion Our study will provide evidence to inform guidance given to women diagnosed with cancer on the safety of HRT use and/or guide modifications to clinical practice.


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