cardiovascular-agents and symmetric-dimethylarginine

The asymmetric methylarginines inhibit nitric oxide synthesis in vivo by competing with L-arginine at the active site of nitric oxide synthase. High circulating levels of asymmetric dimethylarginine predict adverse outcomes, specifically vascular events but there is now increasing experimental and epidemiological evidence that these molecules, and the enzymes that regulate this pathway, play a mechanistic role in cardiovascular diseases. Recent data have provided insight into the impact of altered levels of these amino acids in both humans and rodents, however these reports also suggest a simplistic approach based on measuring, and modulating circulating asymmetric dimethylarginine alone is inadequate. This review outlines the basic biochemistry and physiology of endogenous methylarginines, examines both the experimental and observational evidence for a role in disease pathogenesis, and examines the potential for therapeutic regulation of these molecules.

Topics: Amidohydrolases; Animals; Arginine; Binding Sites; Binding, Competitive; Biomarkers; Cardiovascular Agents; Cardiovascular Diseases; Catalytic Domain; Enzyme Inhibitors; Humans; Nitric Oxide; Nitric Oxide Synthase; omega-N-Methylarginine

Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide (NO) which plays an important role in controlling vascular tone and regulates the contractile properties of cardiac myocytes. The aim of this study was to investigate the effect of pharmacological treatment on symmetric dimethylarginine (SDMA), ADMA and arginine plasma concentrations in patients with acute congestive heart failure (ACHF) through the evaluation of type-1 system cationic amino acid transporter-1/type 1 dimethylarginine dimethylaminohydrolases-1 (CAT-1/DDAH-1).. 25 hospitalized cardiology patients with symptomatic acute congestive HF (NYHA Class III-IV) and impaired left ventricular (LV) function (ejection fraction<35%) were included in the study. ADMA, SDMA, and arginine plasma concentrations were assessed before and after pharmacological treatment by high performance liquid chromatography. All patients received an adequate pharmacological treatment for ACHF. ADMA and SDMA plasma levels were significantly higher after pharmacological treatment respect to baseline values (pre-treatment) (0.75 vs 0.48; 1.31 vs 1.03; p<0.01). Arginine plasma concentration was significantly lower after therapy respect to baseline values (0.78 vs 0.99; p<0.01). This is associated more with the modulation of DDAH-1 protein than with of CAT-1 system transport.. In patients with ACHF, acute renal impairment function and the modulation of metabolism and extracellular transport by the DDAH-1/CAT-1 system determine high ADMA and SDMA levels after therapy for acute congestive heart failure.

Topics: Acute Disease; Aged; Amidohydrolases; Arginine; Cardiovascular Agents; Cationic Amino Acid Transporter 1; Chromatography, High Pressure Liquid; Echocardiography, Doppler; Female; Heart Failure; Humans; Italy; Male; Middle Aged; Stroke Volume; Treatment Outcome; Ventricular Function, Left