@article{WengKoestlerBleyetal.2021, author = {Weng, Andreas M. and K{\"o}stler, Herbert and Bley, Thorsten A. and Ritter, Christian O.}, title = {Effect of short-term smoking \& L-arginine on coronary endothelial function assessed by cardiac magnetic resonance cold pressor testing: a pilot study}, series = {BMC Cardiovascular Disorders}, volume = {21}, journal = {BMC Cardiovascular Disorders}, doi = {10.1186/s12872-021-02050-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-260559}, year = {2021}, abstract = {Background The effect of smoking on coronary vasomotion has been investigated in the past with various imaging techniques in both short- and long-term smokers. Additionally, coronary vasomotion has been shown to be normalized in long-term smokers by L-Arginine acting as a substrate for NO synthase, revealing the coronary endothelium as the major site of abnormal vasomotor response. Aim of the prospective cohort study was to investigate coronary vasomotion of young healthy short-term smokers via magnetic resonance cold pressor test with and without the administration of L-Arginine and compare obtained results with the ones from nonsmokers. Methods Myocardial blood flow (MBF) was quantified with first-pass perfusion MRI on a 1.5 T scanner in healthy short-term smokers (N = 10, age: 25.0 ± 2.8 years, 5.0 ± 2.9 pack years) and nonsmokers (N = 10, age: 34.3 ± 13.6) both at rest and during cold pressor test (CPT). Smokers underwent an additional examination after administration of L-Arginine within a median of 7 days of the na{\"i}ve examination. Results MBF at rest turned out to be 0.77 ± 0.30 (smokers with no L-Arginine; mean ± standard deviation), 0.66 ± 0.21 (smokers L-Arginine) and 0.84 ± 0.08 (nonsmokers). Values under CPT were 1.21 ± 0.42 (smokers no L-Arginine), 1.09 ± 0.35 (smokers L-Arginine) and 1.63 ± 0.33 (nonsmokers). In all groups, MBF was significantly increased under CPT compared to the corresponding rest examination (p < 0.05 in all cases). Additionally, MBF under CPT was significantly different between the smokers and the nonsmokers (p = 0.002). MBF at rest was significantly different between the smokers when L-Arginine was given and the nonsmokers (p = 0.035). Conclusion Short-term smokers showed a reduced response to cold both with and without the administration of L-Arginine. However, absolute MBF values under CPT were lower compared to nonsmokers independently of L-Arginine administration.}, language = {en} } @article{DrechslerKolleritzMeinitzeretal.2013, author = {Drechsler, Christiane and Kolleritz, Barbara and Meinitzer, Andreas and M{\"a}rz, Winfried and Ritz, Eberhard and K{\"o}nig, Paul and Neyer, Ulrich and Pilz, Stefan and Wanner, Christoph and Kronenberg, Florian}, title = {Homoarginine and Progression of Chronic Kidney Disease: Results from the Mild to Moderate Kidney Disease Study}, series = {PLoS ONE}, volume = {8}, journal = {PLoS ONE}, number = {5}, organization = {MMKD Study Group}, doi = {10.1371/journal.pone.0063560}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-130979}, pages = {e63560}, year = {2013}, abstract = {Background: Homoarginine is an amino acid derivative mainly synthesized in the kidney. It is suggested to increase nitric oxide availability, enhance endothelial function and to protect against cardiovascular diseases. We aimed to investigate the relation between homoarginine, kidney function and progression of chronic kidney disease (CKD). Methods: We measured plasma homoarginine concentrations in baseline samples of the Mild to Moderate Kidney Disease (MMKD) Study, a prospective cohort study of 227 patients with CKD in Europe. Homoarginine concentrations were available in 182 of the baseline samples and in 139 of the prospectively-followed patients. We correlated homoarginine concentrations to parameters of kidney function. The association between homoarginine and progression of CKD was assessed during a follow-up of up to seven years (median 4.45 years, interquartile range 2.54-5.19) using Cox regression analysis. Progression of CKD was defined as doubling of baseline serum creatinine and/or end-stage renal disease. Results: Study participants were at baseline on average 47 \(\pm\)13 years old and 65\% were male. Mean \(\pm\) standard deviation of homoarginine concentrations were \(2.5 \pm 1.1 \mu mol/L\) and concentrations were incrementally lower at lower levels of GFR with mean concentrations of \(2.90 \pm 1.02 \mu mol/L\) (GFR. 90 ml/min), \(2.64 \pm 1.06 \mu mol/L\) (GFR 60-90 ml/min), \(2.52 \pm 1.24 \mu mol/L\) (GFR 30-60 ml/min) and \(2.05 \pm 0.78 \mu mol/L\) (GFR, 30 ml/min), respectively (p = 0.002). The age-and sex-adjusted risk to reach the renal endpoint was significantly higher by 62\% with each decrease by one standard deviation (\(1.1 \mu mol/L\)) of homoarginine (HR 1.62, 95\% CI 1.16-2.27, p = 0.005). This association was independent of proteinuria (HR 1.56, 95\% CI 1.11-2.20, p = 0.01), and was slightly attenuated when adjusting for GFR (HR 1.40 (95\% CI 0.98-1.98, p = 0.06). Conclusions: Homoarginine concentrations are directly correlated with kidney function and are significantly associated with the progression of CKD. Low homoarginine concentrations might be an early indicator of kidney failure and a potential target for the prevention of disease progression which needs further investigations.}, language = {en} }