István András Szijártó

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Although resveratrol has widely been studied for its potential health benefits, little is known about its metabolic effects in humans. Our aims were to determine whether the polyphenol resveratrol improves insulin sensitivity in type 2 diabetic patients and to gain some insight into the mechanism of its action. After an initial general examination(More)
BACKGROUND Hydrogen sulfide (H(2)S) is a potent vasodilator. However, the complex mechanisms of vasoregulation by H(2)S are not fully understood. We tested the hypotheses that (1) H(2)S exerts vasodilatory effects by opening KCNQ-type voltage-dependent (K(v)) K(+) channels and (2) that H(2)S-producing cystathionine-γ-lyase (CSE) in perivascular adipose(More)
Hydrogen sulfide (H2S) has emerged as a signalling molecule capable of regulating several important physiological functions such as blood pressure, neurotransmission and inflammation. The mechanisms behind these effects are still largely elusive and oxidative posttranslational modification of cysteine residues (protein persulfidation or S-sulfhydration) has(More)
RATIONALE Vascular wall stretch is the major stimulus for the myogenic response of small arteries to pressure. The molecular mechanisms are elusive, but recent findings suggest that G protein-coupled receptors can elicit a stretch response. OBJECTIVE To determine whether angiotensin II type 1 receptors (AT1R) in vascular smooth muscle cells exert(More)
High blood pressure is the leading risk factor for death worldwide. One of the hallmarks is a rise of peripheral vascular resistance, which largely depends on arteriole tone. Ca2+-activated chloride currents (CaCCs) in vascular smooth muscle cells (VSMCs) are candidates for increasing vascular contractility. We analyzed the vascular tree and identified(More)
BACKGROUND In glomerulonephritides, dysmorphic red blood cells (RBCs) with membrane blebs can be found in the urine; this is referred to as glomerular hematuria. Glomerulonephritides are characterized by increased carbonyl stress and elevated methylglyoxal (MGO) levels. MGO causes oxidative stress and intracellular calcium accumulation. In the present(More)
BACKGROUND Non-enzymatic glycation is a process, which leads to the formation of advanced glycation endproducts. These compounds are involved in the development of diabetic microvascular complications. Fructosamine-3-kinase (FN3K) is an intracellular enzyme that phosphorylates fructosamines resulting in fructosamine-3-phosphate, which subsequently(More)
Previous studies have shown that in diabetes mellitus, insulin-induced relaxation of arteries is impaired and the level of ortho-tyrosine (o-Tyr), an oxidized amino acid is increased. Thus, we hypothesized that elevated vascular level of o-Tyr contributes to the impairment of insulin-induced vascular relaxation. Rats were fed with o-Tyr for 4 weeks.(More)
RATIONALE The oxidative state has been implicated in the signaling of various vasomotor functions, yet its role regarding the vasomotor action of insulin is less known. OBJECTIVE To investigate the insulin-evoked relaxations of consecutive arterial segments of different oxidative state and the role of extracellular signal-regulated kinase (ERK) pathway.(More)
BACKGROUND It has been reported that GLP-1 agonist exenatide (exendin-4) decreases blood pressure. The dose-dependent vasodilator effect of exendin-4 has previously been demonstrated, although the precise mechanism is not thoroughly described. Here we have aimed to provide in vitro evidence for the hypothesis that exenatide may decrease central (aortic)(More)