In the kynurenine pathway of tryptophan metabolism, 3-hydroxyanthranilic acid is the substrate for formation of the excitotoxin quinolinic acid by 3-hydroxyanthranilic acid 3, 4-dioxygenase. This study was designed to characterize the effects on 3-hydroxyanthranilic acid after treatment with the 3-hydroxyanthranilic acid 3,4-dioxygenase inhibitor 4, 6-di-bromo-3-hydroxyanthranilic acid (NCR-631) in Sprague-Dawley rats. ...

BACKGROUND: The importance of urea nitrogen reutilization in the amino acid economy of the host remains to be clarified. OBJECTIVE: The objective was to explore the transfer of (15)N from orally administered [(15)N(2)]urea or (15)NH(4)Cl to plasma free and intestinal microbial amino acids. DESIGN: Six men received an L-amino acid ...

Argininosuccinic acid synthetase deficiency (ASD) is a rare disorder of urea cycle metabolism, with pronounced citrullinemia and orotic aciduria being characteristic biochemical features. To further investigate the role of plasma orotic acid and its possible use for monitoring the metabolic status in ASD, we determined plasma orotic acid, amino acid, ...

Assessment of free fatty acid (FFA) concentration and isotopic enrichment is useful for studies of FFA kinetics in vivo. A new procedure to recover the major FFA from plasma for concentration and isotopic enrichment measurements is described and validated. The procedure involves extraction of plasma lipids with hexane, methylation with ...

BACKGROUND: Ethanol abuse and liver cirrhosis cause a reduction of glutathione blood levels; liver cirrhosis induces an alteration of the plasma amino acid pattern. We evaluated whether or not ethanol abuse affects amino acid levels, particularly those that are involved in metabolizing glutathione in the plasma and erythrocytes of chronic ...

This preliminary investigation determined the plasma amino acid concentrations in 136 healthy subjects. The subjects were divided into four groups according to their ages: gr 1; 1-3 years, gr 2; 4-11 years, gr 3; 12-19 years and gr 4; 20-45 years. Comparing among the groups, the results showed that in ...

BACKGROUND: The microdialysis technique has been widely used for in vivo monitoring of the interstitial composition of several tissues. Remarkably high concentrations of taurine and glycerol were reported in a recent human study. As taurine and glycerol are predominantly present in the intracellular space, cellular trauma after probe insertion may ...

Dipyridyl-dithio substrates were cleaved by isolated vesicles of plasma membranes prepared from etiolated hypocotyls of soybean. The cleavage was stimulated by auxins at physiological concentrations. The substrates utilized were principally 2,2'-dithiodipyridine (DTP) and 6,6'-dithiodinicotinic acid (DTNA). The DTP generated 2 moles of 2-pyridinethione whereas the 6,6'-dithiodinicotinic acid generated 2 moles ...

This study examined the seasonal and reproductive influences on individual plasma amino acid concentrations and nitrogen metabolites in a black bear population (Ontario, Canada). During hibernation, 11 of 23 plasma amino acids were significantly higher (13%-108%) in lactating than in nonlactating females, without an alteration in plasma total protein or ...

Pipecolic acid is regarded as a gamma-aminobutyric acid receptor agonist. Stereochemical studies of pipecolic acid were performed in patients with chronic liver diseases. Plasma D- and L-pipecolic acid were significantly elevated in 15 liver cirrhotic patients with no history of hepatic encephalopathy (1.05+/-0.24 micromol/l, 1.58+/-0.13 micromol/l, p < 0.01) and ...

Populations of scavenging seabird species in the North Sea may fluctuate with an artificial food source: the availability of fishery waste. To document this impact, it is necessary to assess the birds' nutritional status during periods with decreased fishing activity. Reference data for this purpose was collected from 22 herring ...

Whole blood (WB) and plasma (P) amino acid transfers across the portal drained viscera and the liver were determined during 6 h of a constant p-aminohippuric acid infusion in three hourly-fed Landrace x Large-White pigs (30.5 kg, mean live weight) surgically prepared with chronically inserted catheters in a mesenteric vein ...

The effect of cold exposure (0 degrees C, 1 h) on free fatty acid (FFA) mobilization and plasma glucose was studied in freely moving male rats injected with adrenergic blockers (phentolamine or propranolol) into the medial preoptic area (MPOA). The rats were implanted with chronic jugular catheters for blood sampling ...

The concentration of 23 free amino acids was measured in homogenates of fetal liver and samples of fetal plasma from 20 pregnancies between 12 and 17 weeks gestation and compared with those found in matched samples of maternal plasma and amniotic fluid. A feto-maternal plasma concentration gradient was observed for ...

Plasma fatty acids from renal and hepatic veins, and arterialized hand vein obtained in 20 subjects before and after insulin infusion were separated by reversed-phase high-performance liquid chromatography following phenacyl esterification. Separation and quantification over the range 1.0-100 nmol per injection of nine fatty acids was achieved within 60 min ...

The plasma amino acid distribution patterns were measured before, during and after flight on the Space Shuttle. The plasma samples were collected from the four payload crewmembers of the 1993 SLS-2 Columbia Shuttle mission. Samples were taken 45, 15 and 8 d before flight; inflight on days 2, 8 and ...

We describe a procedure for the measurement of pyridoxal 5'-phosphate and of 4-pyridoxic acid in human plasma samples. It is based on the conversion of pyridoxal 5'-phosphate to 4-pyridoxic acid 5'-phosphate by cyanide in alkaline medium, followed by a high pressure liquid chromatographic separation, with fluorescence detection at acid pH. ...

Glycosylated amino acids and glycosylated human serum albumin reduce nitrite to nitric oxide under anaerobic conditions. The amount of nitric oxide produced was recorded by generation of nitrosoHb from deoxyHb. Without preincubation after the addition of sodium nitrite, glucose or a mixture of glucose with amino acid or serum albumin ...

Maple syrup urine disease is a rare inborn error of metabolism, characterized by elevated plasma levels of branched chain amino acids and urinary excretion of branched chain keto acids. Plasma amino acid levels in two subjects were followed by deproteinizing plasma, derivatizing the free amino acids with phenylisothiocyanate, and analysis ...

Protein turnover is a cyclic process with a net loss of protein in the (catabolic) fasted state and a net gain in the (anabolic) fed state. In maple syrup urine disease (MSUD) the early block of degradation of the branched-chain amino acids (BCAA) brings about the opportunity for evaluation of ...

Factor VII activity (FVIIc), a reported risk factor for fatal coronary heart disease, increases transiently after a fat-rich meal. The response shows dose-response characteristics and peak FVIIc and triglyceride concentrations above fasting levels tend to be positively associated. The mechanism is incompletely understood, but appears to require factor IX and ...

Previous studies in this laboratory have elicited a monophasic response in postprandial plasma triacylglycerol (TAG) level with fat intakes of 0.5 g fat/kg body weight accompanied by about 17 g carbohydrate as lactose. Recent studies involving the same level of fat with a higher level of carbohydrate, 136 g of ...

To investigate the participation of erythrocytes in the blood transport of amino acids during the course of intestinal absorption in humans, erythrocyte and plasma amino-acid concentrations were determined following ingestion of an oral load of amino acids. In addition to baseline plasma and erythrocyte amino acid concentrations in 18 subjects, ...

The separation of strongly basic, moderately basic, weakly basic, strongly acidic, moderately acidic, weakly acidic, and neutral compounds in a single run using capillary electrochromatography (CEC) is presented. This is accomplished using a 3-μm CEC Hypersil C8 capillary with high organic content acetonitrile/phosphate (pH 2.5) mobile phases containing hexylamine. Fifteen ...

In 41 primary Sjögren's syndrome patients we compared fatty acid levels within erythrocyte phospholipids, plasma phospholipids, plasma triglycerides and plasma cholesterol esters, with the immunopathological and clinical disease status. Docosahexaenoic acid was the essential fatty acid (EFA), the levels of which correlated (inversely) most closely with the clinical disease status ...

OBJECTIVE: To evaluate the amino acid profile in a group of adolescents with anorexia nervosa, and to apply alternative ways of presenting and assessing results, so as to increase the information available for understanding the metabolic abnormalities developed in these patients. DESIGN: Plasma amino acid concentrations of a random group ...

BACKGROUND: In normal subjects, protein loading with soybean meal does not produce the same renal haemodynamic effects as those observed with a beef meal. The renal responses of an acute protein load in the form of chicken meal is unknown. METHODS: To examine whether the renal response to a chicken ...

Intraoperative infusion of amino acids stimulates oxygen uptake with a resulting increase in heat production, especially during emergence from anesthesia. To determine whether the increased thermogenesis in response to amino acid infusion during and after anesthesia induces any additional stress in surgical patients, plasma catecholamines were measured. Fourteen patients aged ...

Homocysteine (Hcy) represents a branching point between the transsulfuration and transmethylation pathway of methionine. A large increase of plasma concentration of Hcy is observed in patients with inherited hyperhomocysteinemia. A moderated increase (above 10 microM) is also observed in various pathological conditions, such as arterial occlusion, hypertension, hyperlipidemia and chronic ...

Ten subjects (from 27 to 41 years) have been participated in 32 experiments. They were decompressed from ground level to 40-35 kPa in altitude chamber when breathed 100% oxygen by mask and performed repeated cycles of exercises (3.0 Kcal/min). The intervals between decompressions were 3-5 days. Plasma lipid and erythrocyte ...

The effect of dietary linoleic (C18:2n-6) and palmitic acids (C16:0) on rate of hepatic de novo fatty acid synthesis was assessed in normal subjects. The diet was formulated to provide combinations of high and low levels of C18:2n-6 and C16:0. After 21 days of diet treatment, plasma triacylglycerol level and ...

Relatively high concentrations of leptin are present in plasma and it is thought to play a major role in lipid homeostasis. Leptin is reported to lower tissue triglyceride content by increasing intracellular oxidation of free fatty acids (FFA). However very little is known regarding the interaction between leptin and plasma ...

PURPOSE: The synthesis of chemically stable triazene prodrugs capable of hydrolysing under physiological conditions to liberate cytotoxic monomethyltriazene alkylating agents. METHODS: A series of 3-aminoacyl-1-aryl-3-methyltriazenes was synthesised through reaction of 1-aryl-3-methyltriazenes with N-BOC protected amino acids using the DCC method of activation, followed by deprotection of the amino function using ...

Infusions of branched chain amino acids (BCAA) have been shown to have several CNS-mediated effects including antinociceptive action. We investigated the effects of BCAA infusion on pain perception, respiratory control, and plasma monoamine concentrations. Six healthy female volunteers were given in a double-blind, random, crossover design an 8-h infusion (1.75 ...

Patients with inflammatory bowel disease (IBD) have increased plasma n3 polyunsaturated fatty acids (PUFAs), which in ulcerative colitis (UC) patients persists six months after colectomy, suggesting a primary abnormality in fatty acid (FA) metabolism in IBD. This finding needed to be confirmed in a larger series of UC long-term colectomized ...

The purpose of this study was to determine the effect of renal function on the elimination and disposition of mycophenolic acid and its glucuronide metabolite (MPAG) after oral administration of the pro-drug mycophenolate mofetil. In addition, this study sought to examine hemodialysis removal of mycophenolic acid and its MPAG. Subjects ...

To explain the increased plasma mitochondrial aspartate aminotransferase (mAspAT) observed in alcoholics, we cultured HepG2 hepatoma cells in ethanol. Acute (24 hour) exposure to 0, 20, 40, or 80 mmol/L ethanol produced a dose-dependent (r = .98) increase in mAspAT messenger RNA (mRNA) of < or = thirteen-fold, with no ...

AIM: There is little information on the plasma free amino acid patterns of elite athletes against which fatigue and nutrition can be considered. Therefore the aim was to include analysis of this pattern in the medical screening of elite athletes during both especially intense and light training periods. METHODS: Plasma ...

OBJECTIVE: To assess the plasma fatty acid status of a group of well-nourished children with the human immunodeficiency virus type-1 (HIV-1) and how this relates to the blood total CD4+ lymphocyte count. SUBJECTS: Fourteen HIV-1 seropositive children at various stages of disease and with adequate growth indices were assessed and ...

OBJECTIVES: Recent reports have suggested that patients treated by CAPD have a relatively increased risk of death compared to patients undergoing HD, although the cause of this discrepancy is poorly understood. Protein malnutrition is an important risk factor in ESRD. Also, amino acid concentrations, for which the physiological function differs ...

The determination of plasma and whole blood free amino acid concentrations in arterial and portal venous blood during post prandial state in the rat was used to estimate the role of the erythrocytes in amino acid exchanges. The erythrocyte contents were calculated from plasma, whole blood concentrations and the hematocrit. ...

The consequences of dietary excesses of 10 essential amino acids, His, Ile, Phe, Trp, Val, Arg, Leu, Lys, Met, Thr, on growth, feed intake and plasma levels of triiodothyronine (T3) and thyroxine (T4) in growing chicks were investigated. Each amino acid was added to a starter ration to bring it ...

We examined whether dietary acid that increases net acid excretion (NAE) without measurably decreasing plasma pH or total CO2 (tCO2) causes net acid retention. Control rats drinking distilled H2O were compared with those drinking 40 mM (NH4)2SO4, 40 mM Na2SO4, or drinking Na2SO4 and given aldosterone (Na2SO4 + Aldo) to ...

The in vitro stability and plasma pharmacokinetics of 5,10-methylenetetrahydrofolic acid (CH2FH4), tetrahydrofolic acid (FH4), 5-methyltetrahydrofolic acid (CH3FH4), and 5-formyltetrahydrofolic acid (5-CHOFH4) were studied in view of their potential usefulness in cancer chemotherapy. Analysis of reduced folates was done on a high-performance liquid chromatography (HPLC) system. The high sensitivity of FH4 ...

Older studies in humans seem to suggest a correlation between plasma long chain fatty acid (LCFA) turnover and oxidation on the one hand and plasma LCFA concentration on the other hand during submaximal exercise. However, recent studies in man, in which higher concentrations of plasma LCFA have been reached during ...

To evaluate the susceptibilities of human blood constituents to the low levels of ozone used in ozonated autohemotherapy (40 microgO3/ml), we quantified plasma antioxidants and erythrocyte constituents after rapid mixing of human whole blood with ozone at 20, 40, 60, and 100 microg/ml blood. Ascorbic acid, uric acid, and alpha-tocopherol ...

Taurine (2-aminoethane sulphonic acid), a ubiquitous beta-amino acid is conditionally essential in man. It is not utilized in protein synthesis but found free or in some simple peptides. Derived from methionine and cysteine metabolism, taurine is known to play a pivotal role in numerous physiological functions. Some of the roles ...

BACKGROUND: We analysed amino-acid losses during haemodialysis, their influence on plasma amino-acid concentration, and their possible effects on nutritional state. METHODS: Five patients were dialysed with three membranes: cuprophan (CUP), polysulphone (PS), and polyacrylonitrile AN69 (PAN). We compared anthropometric and biochemical parameters after 6 months in patients dialysed with CUP ...

Ion-exchange chromatography (IEC) with ninhydrin post-column derivatisation is the only technique available for the assay of total, (free plus bound), cysteine and homocysteine which also enables the routine measurement of all other commonly occurring amino acids. IEC assay of total cysteine and homocysteine typically involves incubating buffered plasma for 60 ...

Plasma amino acids were analysed in patients with migraine with (9) and without (80) aura, in patients with tension headache (14) and in controls (62). The neuroexcitatory amino acids glutamic acid, glutamine, glycine, cysteic acid and homocysteic acid were elevated in migraine patients while total thiols (cysteine/cystine) were reduced. Patients ...