Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P50583 (asymmetrical)
 12,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Eleven patients with thrombotic thrombocytopenic purpura (TTP) or haemolytic uremic syndrome (HUS) were investigated with respect to plasma concentrations of L-arginine, a substrate for nitric oxide (NO) and asymmetrical dimethyl arginine (ADMA), during active disease and after recovery. Plasma concentration of NO3-, the degradation product of NO, was also analyzed. The patients were treated with fresh-frozen plasma and plasmapheresis. One of the patients had experienced relapses of TTP five times during the preceding year. After treatment with p.o. arginine hydrochloride 1.5 g x 3 was started, no relapse has occurred during a 12-month period. During the active phase the plasma concentration of arginine was low and that of NO3- was very high, indicating a high NO-synthesis rate. The arginine concentration normalized on recovery. Plasma levels of ADMA, was twice normal during active disease, and did not return to normal on recovery. In conclusion, patients with TTP/HUS exhibit signs of activation of the NO-synthesis.
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PMID:The arginine-nitric oxide pathway in thrombotic microangiopathy. 940 11

The regulation of nitrate assimilation seems to follow the same pattern in all ascomycetes where this process has been studied. We show here by in vitro binding studies and a number of protection and interference techniques that the transcription factor mediating nitrate induction in Aspergillus nidulans, a protein containing a binuclear zinc cluster DNA binding domain, recognizes an asymmetrical sequence of the form CTCC GHGG. We further show that the protein binds to its consensus site as a dimer. We establish the role of the putative dimerization element by its ability to replace the analogous element of the cI protein of phage lambda. Mutagenesis of crucial leucines of the dimerization element affect both the binding ability of the dimer and the conformation of the resulting protein-DNA complex. This is the first case to be described where a dimer recognizes such an asymmetrical nonrepeated sequence, presumably by each monomeric subunit making different contacts with different DNA half-sites.
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PMID:The regulator of nitrate assimilation in ascomycetes is a dimer which binds a nonrepeated, asymmetrical sequence. 948 49

Whether L-Arginine (L-ARG) ameliorates or aggravates renal function and histopathological changes in several models of renal disease remains controversial as L-ARG is the substrate for nitric oxide (NO) synthase as well as the precursor of proline and polyamines which cause renal fibrosis. These ambiguous results might be attributed to differences in the dose and period of L-ARG administration and the animal model used in each observation. Therefore, we tested the dose-dependent effect of L-ARG on mean blood pressure (MBP), 24-hour urinary excretion of protein (UP), NO metabolites (NO2(-) + NO3-) and cyclic GMP (cGMP), plasma asymmetrical dimethylarginine (ADMA), glomerular sclerosis index (SI) and % interstitial fibrosis area (%INT) in 5/6 nephrectomized SD rats. These 5/6 nephrectomized SD rats were divided into 4 groups: 1. L-ARG 0.2 g/kg/day (0.2 g ARG), 2. L-ARG 1 g/kg/day (1 g ARG), 3. L-ARG 2 g/kg/day (2 g ARG), 4. No administration of L-ARG(ARG(-)). Compared with ARG(-)MBP, UP and ADMA were significantly decreased and NO2(-) + NO3-, cGMP were significantly increased in the 0.2 g ARG. SI group and %INT were significantly increased in the 2 g ARG group and decreased in the 0.2 g ARG group. A small dose of L-ARG ameliorated glomerulosclerosis and interstitial fibrosis while a larger dose did not. SI, %INT and ADMA were inversely correlated with NO2(-) + NO3-. These data suggested that renal NO synthesis might attenuate glomerulosclerosis and interstitial fibrosis and the rise in ADMA and L-ARG might cause the decrease in NO.
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PMID:[Paradoxical effect of L-arginine on nitric oxide (NO) synthesis and histopathological changes in 5/6 nephrectomized SD rats]. 1065 23

Nitric oxide (NO) is derived from the metabolism of the amino acid L-arginine by NO synthase (NOS). One of the forms of NOS (i-NOS) can be induced by cytokines, bradykinin and endotoxin. During hemodialysis (HD), blood-dialysis membrane interaction can induce production of these mediators. HD can also induce changes of asymmetrical dimethylarginine (ADA), a potent inhibitor of NOS. The aim of this study was to investigate the effect of HD, using cuprophane (C, polyacrilonytrile (PAN) and special polyacrylonitrile (SPAN) membranes, on cellular NOS activity, and changes of plasma tumor necrosis factor (TNF-alpha), bradykinin, ADA and nitrate concentration. Before HD, cellular i-NOS activity was similar with the three membranes. Cuprophane HD induced a significant increase in i-NOS activity from 31 +/- 10 to 48 +/- 12 fmol-1 10(6) cells (p < 0.05). No changes were found in PAN and SPAN HD. The TNF-alpha values increased significantly during HD with C (56 +/- 6 vs 47 +/- 5 pg/ml, p < 0.05). No changes of bradykinin concentration were found during HD. A significant decrease of ADA and nitrate levels was observed during HD with three membranes. No significant correlation was found between percentage increase in i-NOS activity and the changes in other parameters. These findings suggest that HD with bioincompatible membranes can induce activation of cellular i-NOS.
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PMID:[L-arginine-nitric oxide pathway in hemodialysis]. 1091 3

1. The aim of the present study was to examine the acute effects of cortisol infusion on plasma nitrate/nitrite (NO) activity and forearm vascular responsiveness to acetylcholine. 2. We performed two randomized, placebo-controlled, cross-over studies. Study A examined the effects of intravenous hydrocortisone (200 mg over a 3 h period) on blood pressure (BP) and plasma NO activity in six healthy male volunteers. Study B examined the effects of intra-arterial hydrocortisone on cholinergic vasodilator responsiveness in six healthy male volunteers. Vasodilator responsiveness was measured by bilateral strain gauge plethysmography. 3. In study A, there was no significant change in BP during the hydrocortisone infusion. Comparing values obtained following 180 min infusion of hydrocortisone and control, there were significant increases in plasma cortisol (3441 +/- 342 vs 209 +/- 29 nmol/L, respectively; P < 0.001) and glucose (5.7 +/- 0.2 vs 4.6 +/- 0.2 mmol/L, respectively; P < 0.05) and a reduction in plasma renin concentration (PRC) (8.1 +/- 1.2 vs 11.0 +/- 1.8 pg/mL, respectively; P < 0.05) following hydrocortisone infusion. However, there were no significant changes in either plasma NO or in the endogenous NO synthase inhibitors asymmetrical and symmetrical dimethylarginine. 4. In study B, there was no significant change in BP or in cholinergic vasodilator responsiveness during the hydrocortisone infusion. 5. Short-term cortisol infusions do not alter biochemical or physiological markers of NO activity. If cortisol-induced hypertension is mediated by suppression of NO activity in humans, it seems likely that these changes take more than 3 h to become detectable.
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PMID:Acute effects of hydrocortisone on plasma nitrate/nitrite activity and forearm vasodilator responsiveness in normal human subjects. 1574 97

Reactions of Hg(OAc)2 with 2 equiv of TabHPF6 [TabH = 4-(trimethylammonio)benzenethiol] in MeCN/MeOH afforded a mononuclear linear complex [Hg(Tab)2](PF6)2 (1). By using 1 as a precursor, a new family of mercury(II) zwitterionic thiolate complexes, [Hg2(Tab)6](PF6)4.2MeCN (2.2MeCN), [Hg(Tab)2(SCN)](PF6) (3), [Hg(Tab)2(SCN)2] (4), [Hg(Tab)I2] (5), {[Hg(Tab)2]4[HgI2][Hg2I6]}(PF6)2(NO3)4 (6), [Hg(Tab)2][HgI4] (7), [Hg(Tab)2][HgCl2(SCN)2] (8), [Tab-Tab]2[Hg3Cl10] (9), and [Hg2(Tab)6]3(PF6)Cl11 (10), were prepared and characterized by elemental analysis, IR spectra, UV-vis spectra, 1H NMR, and single-crystal X-ray crystallography. The [Hg2(Tab)6]4+ tetracation of 2 or 10 contains an asymmetrical Hg2S2 rhomb with an inversion center lying on the midpoint of the Hg...Hg line. The Hg atom of the [Hg(Tab)2]2+ dication of 3 is coordinated to one SCN-, forming a rare T-shaped coordination geometry, while in 4, the Hg atom of [Hg(Tab)2]2+ is coordinated to two SCN-, forming a seesaw-shaped coordination geometry. Through weak secondary Hg...S coordinations, each cation in 3 is further linked to afford a one-dimensional zigzag chain. The trigonal [Hg(Tab)I2] molecules in 5 are held together by weak secondary Hg...I and Hg...S interactions, forming a one-dimensional chain structure. In 6, the four [Hg(Tab)2]2+ dications, one HgI2 molecule, one [Hg2I6]2- dianion, one PF6-, and four NO3- anions are interconnected by complicated secondary Hg...I and Hg...O interactions, forming a scolopendra-like chain structure. The secondary Hg...I interactions, [Hg(Tab)2]2+ and [HgI4]2- in 7, are combined to generate a one-dimensional chain structure, while [Hg(Tab)2]2+ and [HgCl2(SCN)2]2- in 8 are interconnected by secondary Hg...N interactions to form a one-dimensional zigzag chain structure. Compound 9 consists of two [Tab-Tab]2+ dications and one [Hg3Cl10]4- tetraanion. The facile approach to the construction of 2-8 and 10 from 1 may be applicable to the mimicking of a coordination sphere of the Hg sites of metallothioneins.
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PMID:Assembly of a new family of mercury(II) zwitterionic thiolate complexes from a preformed compound [Hg(Tab)2](PF6)2 [Tab = 4-(trimethylammonio)benzenethiolate]. 1652 78

Colloidal gold was prepared by sodium citrate-induced reduction of hydrogen tetrachloroaurate. Colloidal silver was prepared by the reduction of silver nitrate by sodium borohydride respectively. The gold and silver sols were characterized by means of UV-Vis, SEM and CVs. Results show that the gold and silver colloids were a monodisperse suspension with the average size of 16 and 10 nm respectively; Ordered sub-monolayer structure of gold and silver nanoparticles on the ITO was fabricated by self-assembly technique. The CV character of gold and silver nanoparticles features a pair of asymmetrical ox-red peaks separately, moreover, the positions of these peaks are influenced by the concentrations of gold and silver nanoparticles. Ordered double-layer structures of gold/silver nanoparticles on roughened gold substrates were obtained by self-assembly method, where benzidine was used as the coupling molecules. The results of surface-enhanced Raman spectroscopic characterization show that Raman scattering of benzidine molecules during self-assembly is enhanced.
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PMID:[Electrochemical character of gold/silver nanoparticles and SERS studies on benzidine]. 1736 20

Dimethylarginine dimethylaminohydrolase (DDAH) is an enzyme that metabolizes asymmetrical N(G),N(G)-dimethyl-L-arginine (ADMA) and N(G)-monomethyl-L-arginine (MMA), which are competitive endogenous inhibitors of NO synthase. However, it remains unknown whether NO itself influences DDAH activity and/or ADMA/MMA contents to regulate NO generation via a biofeedback mechanism. The present study was designed to examine the effects of NO on intracellular ADMA and MMA contents and DDAH gene expression levels and enzymatic activities in cultured rat aortic endothelial cells. The NO donors SNAP and NOR3 did not influence DDAH-1 expression but increased DDAH-2 mRNA and protein levels in concentration-dependent manners. SNAP upregulated DDAH enzymatic activity and reduced the MMA and ADMA contents but did not affect the symmetrical N(G),N'(G)-dimethyl-L-arginine and L-arginine levels, thereby negating a mediatory role for system y(+) in ADMA/MMA downregulation. The cGMP agonists 8-bromo-cGMP and C-type natriuretic peptide also stimulated DDAH-2 gene and protein expression levels and DDAH activity and increased the amount of nitrite/nitrate released into the culture supernatants. SNAP-induced DDAH-2 gene expression and DDAH activity were significantly inhibited by a protein kinase G inhibitor, KT5823, and a soluble guanylate cyclase inhibitor, ODQ, suggesting a mediatory role for cGMP in NO-induced DDAH-2 expression. Suppression of DDAH-2 mRNA using small interfering RNA technology abrogated NO-induced DDAH-2 expression. These data demonstrate that NO acts on endothelial cells to induce DDAH-2 expression via a cGMP-mediated process to reduce ADMA/MMA. Thus, the DDAH-2-ADMA/MMA-endothelial NO synthase regulatory pathway and NO-induced cGMP constitute a positive feedback loop that ultimately serves to maintain NO levels in the endothelial environment.
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PMID:Nitric oxide upregulates dimethylarginine dimethylaminohydrolase-2 via cyclic GMP induction in endothelial cells. 1882 64

Atrial fibrillation (AF) may cause thrombus formation in the left atrial appendage (LAA). Thrombus formation is associated with LAA endocardial dysfunction. Because asymmetrical dimethylarginine (ADMA) can cause endothelial dysfunction by decreasing nitric oxide (NO) formation, we investigated plasma ADMA and nitrite/nitrate (NO(X)) levels and myocardial dimethylarginine dimethylaminohydrolase-2 (DDAH-2), protein arginine methyltransferase-1 (PRMT-1), and endothelial NO synthase (eNOS) protein contents from AF dogs. The results displayed that plasma ADMA level significantly increased, and plasma NO(X) concentration significantly decreased. Compared with normal heart, DDAH-2 expression was unchanged in the fibrillating atria. However, the DDAH activity was significantly decreased in the fibrillating atria. PRMT-1 expression significantly increased in the LAA and in the left atrium (LA). ENOS expression significantly decreased in the LA. ENOS and PRMT-1 expressions were unchanged in the right atria. Our results suggested that the DDAH-PRMT-ADMA system maybe play a pivotal role in regulating endothelial function in AF.
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PMID:Variance of DDAH/PRMT/ADMA pathway in atrial fibrillation dogs. 1895 71

Meiotic and mitotic chromosomes of Dichotomius nisus, D. semisquamosus and D. sericeus were analyzed after conventional staining, C-banding and silver nitrate staining. In addition, Dichotomius nisus and D. semisquamosus chromosomes were also analyzed after fluorescent in situ hybridization (FISH) with an rDNA probe. The species analyzed had an asymmetrical karyotype with 2n = 18 and meta-submetacentric chromosomes. The sex determination mechanism was of the Xy(p) type in D. nisus and D. semisquamosus and of the Xy (r) type in D. sericeus. C-banding revealed the presence of pericentromeric blocks of constitutive heterochromatin (CH) in all the chromosomes of the three species. After silver staining, the nucleolar organizer regions (NORs) were located in autosomes of D. semisquamosus and D. sericeus and in the sexual bivalent of D. nisus. FISH with an rDNA probe confirmed NORs location in D. semisquamosus and in D. nisus. Our results suggest that chromosome inversions and fusions occurred during the evolution of the group.
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PMID:Comparative cytogenetics of three species of Dichotomius (Coleoptera, Scarabaeidae). 2163 80


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