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PubMed1976

Ion-pair partition chromatography in the analysis of drugs and biogenic substances in plasma and urine.

Liquid-liquid chromatography based on the ion-pair partition technique gives separation systems of high efficiency when silica micro-particles are used as the support for the stationary phase. With 10-mum particles, plate heights of the order of 40-70 mum have been achieved with a linear velocity of 0.25 cm/sec. The retention in ion-pair partition systems is determined by the nature and concentration of the counter ion, and the properties of the mobile phase also have a major influence. It is often possible to predict the selectivity, and this can be controlled by varying the composition of the mobile phase. This paper describes the application of ion-pair partition chromatography to the bioanalysis of drugs, drug metabolites and biogenic substances. Typical counter ions in the stationary phase were methanesulphonate and perchlorate for ammonium compounds and tetrabutylammonium for the separation of organic anions. Determinations by liquid chromatography were demonstrated for quinidine and dihydroquinidine, metanephrine and normetanephrine and for imipramine and its demethyl metabolite in plasma. A quaternary ammonium compound, QX-572, was determined in urine and chromatograms are shown for the isolation of indoleacetic and hydroxyindoleacetic acid in urine. The methods have been used in routine analysis. Ultraviolet detection has permitted the determination of highly absorbing compounds down to the 10-ng level in plasma and urine.

Absorption↗
PubMed1988

High-performance liquid chromatography of biogenic amines, derivatized with 9-fluorenylmethyl chloroformate.

A procedure was elaborated for the analysis of three biogenic amines posing a considerable health hazard. The method takes advantage of the characteristics of the 9-fluorenylmethyl chloroformate (FMOC) derivative, namely specificity, stability and compatibility for either fluorescence or UV-absorbance detection. The FMOC-tyramine derivative was probably adsorbed to labware when acetone served as the solvent for FMOC. Methanol, substituted for acetone, removed this problem. Excellent linearity was obtained with standard solutions of tyramine, tryptamine and phenylethylamine. Meat samples, spiked with the mentioned amines, also showed good linearity. Perchloric acid was chosen for deproteinization, as potassium perchlorate may be eliminated on neutralization. Histamine failed to react with FMOC or was not detected under the test conditions.

Animals↗
PubMed1986

Determination of biogenic amines in cheese and some other food products by high-performance liquid chromatography in combination with thermo-sensitized reaction detection.

A simple high-performance liquid chromatographic (HPLC) analysis is described for biogenic amines in cheese and other food products. The sample clean-up consists of a precipitation-extraction step with trichloroacetic acid, which gives recoveries of amines in cheese in the range of 85-105%. The HPLC analysis is performed by reversed-phase ion-pair chromatography, using a ninhydrin-containing eluent, which eliminates the need for an extra reagent pump for the post-column derivatization. Band broadening is minimized by using a poly(tetrafluoroethylene) knitted tube reactor at 145 degrees C. The detection limit for amines is 2 mg/kg cheese and the method is linear for 0.1-4 micrograms of amine injected. Examples are given of the analysis of amines in cheese, wine and sauerkraut.

Biogenic Amines↗
PubMed1986

Simultaneous determination of biogenic amines and morphine in discrete rat brain regions by high-performance liquid chromatography with electrochemical detection.

A simple and sensitive method has been developed for the simultaneous determination of norepinephrine, epinephrine, dopamine, 5-hydroxytryptamine, 5-hydroxyindoleacetic acid, and morphine in discrete rat brain regions by reversed-phase high-performance liquid chromatography with electrochemical detection. Perchloric acid extracts of the tissue were directly injected into the chromatographic system. Each of these compounds gave a linear response over the range of 20-160 ng/ml cerebellar homogenate (0.4-3.2 ng on column). Recoveries of these compounds, added to the homogenates, were complete when compared with standards dissolved in perchloric acid. The average between-run coefficients of variation for all these compounds were lower than 7.4% over the range of 20-160 ng/ml, and the within-run coefficients of variation at 20 ng/ml were lower than 8.7%. The present method has been applied to a study of the effects of intraperitoneal administration of morphine on biogenic amines in several discrete rat brain regions.

Animals↗
PubMed2001

Application of capillary electrophoresis with laser-induced fluorescence detection to the determination of biogenic amines and amino acids in brain microdialysate and homogenate samples.

A procedure is described to derivatize 16 primary-amine-containing biogenic amines and amino acids in brain mixtures with the fluorogenic reagent 5-furoylquinoline-3-carboxaldehyde (FQ). These FQ-tagged compounds in the brain sample were resolved in less than 16 min based on micellar electrokinetic chromatography and laser-induced fluorescence. There was a linear relationship between the concentration of analyte and the fluorescence intensity, with correlation coefficients in the range of 0.96-1.00. The utility of this method for the quantification of the important inhibitory neurotransmitter gamma-aminobutyric acid in microdialysates and brain homogenates from rats is illustrated.

Amino Acids↗
PubMed1989

Biogenic amines and their metabolites in body fluids of normal, psychiatric and neurological subjects.

The biogenic monoamines and their metabolites have been isolated, identified and quantified in human body fluids over the past forty years using a wide variety of chromatographic separation and detection techniques. This review summarizes the results of those studies on normal, psychiatric and neurological subjects. Tables of normal values and the methods used to obtain them should prove to be useful as a reference source for benchmark amine and metabolite concentrations and for successful analytical procedures for their chromatographic separation, detection and quantification. Summaries of the often contradictory results of the application of these methods to psychiatric and neurological problems are presented and may assist in the assessment of the validity of the results of experiments in this field. Finally, the individual, environmental and the methodological factors affecting the concentrations of the amines and their metabolites are discussed.

Biogenic Amines↗
PubMed1987

Rapid and sensitive method for measuring norepinephrine, dopamine, 5-hydroxytryptamine and their major metabolites in rat brain by high-performance liquid chromatography. Differential effect of probenecid, haloperidol and yohimbine on the concentrations of biogenic amines and metabolites in various regions of rat brain.

A rapid and sensitive method has been developed for the simultaneous determination of norepinephrine, dopamine, 5-hydroxytryptamine and their respectively metabolites 3-methoxy-4-hydroxyphenylglycol, homovanillic acid, 3,4-dihydroxyphenylacetic acid, and 5-hydroxyindoleacetic acid in discrete brain regions of rats. The supernatants of tissue homogenates were injected directly into a reversed-phase liquid chromatography system, coupled with electrochemical detection. Each of these compounds gave a linear response over the range 5.5-200 ng/ml cerebellar homogenate (0.11-4.0 ng on column). Analytical recoveries of these compounds, added to the homogenate, were essentially complete when compared with standards dissolved in perchloric acid. The average between-assay coefficients of variation for all these compounds were lower than 6.9% over the range 5.5-200 ng/ml. The within-assay coefficients of variation were lower than 9.7%, measured at 5.5 or 23.6 ng/ml. With the present test parameters and mobile phase conditions, all compounds were readily oxidized at 0.8 V vs. a Ag/AgCl reference electrode. The method was applied to an analysis of the differential activity of biogenic amines in the rat striatum, hypothalamus, and hippocampus, produced by probenecid, haloperidol and yohimbine.

Animals↗
PubMed2003

Ion-pair high-performance liquid chromatographic determination of biogenic amines and polyamines in wine and other alcoholic beverages.

An optimised ion-pair reversed-phase high-performance liquid chromatographic method with automatic o-phthalaldehyde post-column derivatization and spectrofluorometric detection for the same-run separation and quantification of 12 biogenic amines and polyamines in alcoholic beverages has been validated. The reliability of the method was satisfactory in terms of linearity (from 0.5 to 15 mg/l), precision (relative standard deviation below 5%), recovery (from 98.7 to 101.1%), and sensitivity (detection limit between 0.03 and 0.06 mg/l). The automatic accomplishment of the derivatization step reduces time and effort of analysis, especially thanks to the easy preparation of the sample.

Alcoholic Beverages↗
PubMed2000

Optimization of chromatographic parameters for the determination of biogenic amines in wines by reversed-phase high-performance liquid chromatography.

A method suitable for the determination of eight biogenic amines (histamine, tyramine, phenylethylamine, tryptamine, cadaverine, putrescine, spermidine and spermine) in wines has been developed. The method involves derivatization of the amines by treatment with dabsyl chloride, after which the derivates were analysed by reversed-phase liquid chromatography with gradient elution and spectrophotometric detection at 446 nm. Different variables affecting separation were optimized. Validation of the method included calibration experiments, the addition of standards amines for the determination of recovery and repeatability tests. Good linearity of the responses was obtained up to 500 microg l(-1), except for putrescine (up to 2100 microg l(-1)). The detection limits ranged between 10 and 60 microg l(-1) for standard solutions. The method was successfully applied to the analysis of five Spanish wines.

Biogenic Amines↗
PubMed1998

Biogenic amines and thermoregulatory changes.

This review recapitulates the general principles of the organization of the thermoregulatory system, describes the thermoregulatory reactions of small and large mammals to hot environment and analyzes the probable roles of biogenic amines in these responses. Catecholamines found in peripheral blood plasma or excreted in urine represent a spillover of mediators released partly from sympathetic nerve endings and partly from the adrenal medulla. Since the thermoregulatory efforts differ between small and large mammals in cold and hot environments, the peripheral release of catecholamines is also different in these animals. The levels of these signal substances in the blood, as well as their peripheral metabolic and functional effects, serve as feedback signals for the hypothalamic integrative circuitry. The roles of antagonistic modulatory monoaminergic systems, ascending from the lower brain stem to the hypothalamus, in these integrations were discussed only partly, because this was a topic of another recent review (Zeisberger and Roth, 1996).

Animals↗
PubMedDate not supplied

Tourette's medications: effect on minor oxidative and reductive pathways of biogenic amines.

The effect of acute treatment of two major Tourette's drugs, haloperidol and pimozide given 60 mg/kg, IP over 48 hr, on hepatic alcohol dehydrogenase (L-ADH) and aldehyde dehydrogenase was studied in the female mouse. The effect of these drugs on heart cytoplasmic lactate dehydrogenase (H-LDH) isoenzyme LDH1 (M) and LDH2 (H) was also measured. Both haloperidol and pimozide significantly inhibited cytoplasmic L-ADH and L-ALDH from controls. Conversely, the haloperidol treatment was associated with induction of both H-LDH isoenzymes studied. Injection of pimozide, 25 mg/kg, IP, to rats with preference to ethanol drinking, caused aversion to voluntary intake of 5% ethanol consumption. This suggests that pimozide produced inhibition of L-ADH in another species and thereby causing aversion to ethanol drinking or may be related to dopaminergic antagonist property. This inhibition of these drugs on the oxidative and reductive pathways of biogenic amine aldehydes may be implicated in and/or associated with the underlying mechanism(s) of action.

Alcohol Dehydrogenase↗
PubMed2002

Improved electrochemical detection of biogenic amines in Aplysia using base-hydrolyzed cellulose-coated carbon fiber microelectrodes.

A major challenge with electrochemical techniques in vivo, using carbon-fiber microelectrodes, is to achieve sufficient sensitivity to detect the low concentrations of transmitters released by neurons. In particular, when an electrode is inserted into living tissue, its sensitivity is usually substantially decreased as a result of the degradation of the carbon surface by proteins. Here, we show that this decrease can be significantly attenuated by coating the electrode with cellulose acetate. The cellulose film offers a steric barrier that prevents macromolecules from diffusing to the carbon surface and its porosity can be progressively increased by controlled hydrolysis. We compared different cellulose-coated electrodes, either non-hydrolysed or hydrolyzed, in 0.08 N KOH for 10-30 min. We found that dopamine and serotonin detection was blocked by non-hydrolysed cellulose films, but that hydrolysis restored optimal detection similar to uncoated electrodes. Moreover, cellulose films (hydrolyzed for 20 min) significantly diminished electrode degradation in vivo and allowed reliable detection of fast concentration changes with <0.5 s delay, compared to uncoated electrodes. Finally, the sensitivity to endogenous 5-HT release in Aplysia central nervous system was more than doubled with these electrodes. We conclude that the optimal hydrolysis time of cellulose-coated electrodes is approximately 20 min with our protocol and carbon fiber electrodes prepared with this method offer improved sensitivity for the detection of biogenic amines.

Animals↗
PubMedDate not supplied

Evaluation of acrylamide treatment on levels of major brain biogenic amines, their turnover rates, and metabolites.

Acrylamide, a widely used and chemically active substance, has caused delayed distal neuropathy in man and in experimental animals. Male rats administered 50 mg/kg/day acrylamide for 5 days demonstrated ataxia in preliminary rotorod experiments. Additional groups of rats were dosed with 5, 15 or 50 mg/kg/day acrylamide for 5 days, then sacrificed on day 6 at various time intervals after iv injections of tritiated tyrosine (Tyr) or tryptophan (Trp). Brain levels of Tyr, Trp, norepinephrine (NE), dopamine (DA), serotonin (5-HT), and respective metabolites, 3-methoxy-4-hydroxyphenylethyleneglycol sulfate (MOPEG-sulfate), 3,4-dihydroxyphenylacetic acid (DOPAC), and 5-hydroxyindoleacetic acid (5-HIAA) were assayed fluorometrically. Turnover rates of NE, DA and 5-HT were estimated by evaluating the rates of specific activity changes in neurotransmitters and precursor amino acids over time. A slight reduction of whole brain NE content was observed in rats administered 50 mg/kg/day acrylamide. Other neurotransmitter levels were not affected by acrylamide levels administered, nor were turnover rates affected. Levels of MOPEG-sulfate and DOPAC were unchanged at any dose tested. Increased levels of 5-HIAA were observed in rats receiving 15 and 50 mg/kg/day acrylamide. Results suggest that acrylamide neurotoxicity does not entail widespread damage to the neurons associated with these biogenic amines; however, the acid metabolite efflux from brain was significantly inhibited.

Acrylamide↗
PubMed1997

Levels of biogenic amines in larvae and adults of the rat hookworm, Nippostrongylus brasiliensis (Nematoda).

Norepinephrine, 5-hydroxytryptophan, octopamine, dihydroxyphenylacetic acid, N-acetyldopamine, dopamine, 5-hydroxyindoleacetic acid, N-acetylserotonin, tyramine, tryptophan and serotonin in larvae (third free stage and parasitic stages) and adult males and females (at defined ages during the intestinal phase) of the parasitic nematode Nippostrongylus brasiliensis were quantified simultaneously by high-performance liquid chromatography with electrochemical detection. Biogenic amine levels depended on the stage, the age and the sex of parasites and on environmental conditions. Their physiological roles in reproductively competent adults of this nematode are discussed in relation to exuviation and egg laying. Parallel fluctuations in free ecdysteroids and norepinephrine were observed in females from the same worm populations.

3,4-Dihydroxyphenylacetic Acid↗
PubMed2000

Electromigration methods for amino acids, biogenic amines and aromatic amines.

Methods of electromigration in laboratory apparatus of small-bore size have recently undergone development at a remarkably rapid pace, leading to a variety of new analytical techniques. One such technique is called "capillary electrophoresis" (CE), which is further classified on the basis of electromigration mode, viz., "capillary zone electrophoresis" (CZE), which, in turn, has several variations. This review aims to give a short overview of the various electromigration methods for amino compounds by using CE. Firstly, this review briefly summarizes the detection methods employed for detection of monoamines and polyamines by CE for both native and derivative forms. Next, current CE methods are described, and their applications to detection of amino acids, biogenic amines, aromatic amines, including heteroaromatic amines and their enantiomers, are introduced from representative papers. Finally, new methods for single-cell analysis and microchip CE techniques are focused on.

Amines↗
PubMed2000

Determination of biogenic amines in fish implicated in food poisoning by micellar electrokinetic capillary chromatography.

A micellar electrokinetic capillary chromatography (MECC) method for the simultaneous determination of seven biogenic amines in fish was developed. The peaks of all components were successfully separated within 11.5 min. MECC was performed with 0.06 M sodium deoxycholate in 0.02 M borate buffer (pH 9.2)-methanol (95:5, v/v) solvent. The average recoveries for all components ranged from 84.4 to 100.3%. The application of this method to detect amines in fried marlin fillet implicated in a food poisoning incident indicated that a high level (56.24 mg/100 g) of histamine was present in the sample. Another 10 fish samples collected from markets were also analyzed and did not contain detectable levels of histamine (<2.5 mg/100 g).

Animals↗
PubMed1982

Pre-column derivatization and high-performance liquid chromatography of biogenic amines in blood of normal and malignant hyperthermic pigs.

A sensitive, selective, pre-column derivatization method was used with high-performance liquid chromatography to measure norepinephrine, dopamine and serotonin in plasma from normal and malignant hyperthermic (MH) pigs. Samples were carefully collected from control and stressed animals under halothane anesthesia. Using a simple extraction method involving pre-column derivatization with o-phthaladehyde and ethyl acetate partitioning, the samples were chromatographed in less than 50 min. Norepinephrine was found to be elevated in MH pigs as the syndrome progressed, reaching levels eight-fold greater than control pigs under anesthesia. These experiments provide some evidence for our hypothesis that a failure to metabolize excess norepinephrine may be one of the key metabolic defects in causing the pathophysiology of the malignant hyperthermia-stress syndrome. The application of our chromatographic method in animal and human tests may provide a pattern of biogenic amine types and levels that could be diagnostic in identifying susceptible humans and carrier animals.

Animals↗
PubMed1986

High-performance liquid chromatography of biogenic amines and metabolites in brain, cerebrospinal fluid, urine and plasma.

A method for high-performance liquid chromatographic separation and electrochemical detection of biogenic amines and metabolites in a variety of biological matrices is described. The method employs either homogenization, precipitation or dilution followed by direct injection of the samples and permits the chromatographic resolution of dopamine, norepinephrine, epinephrine, serotonin (5-HT), 3,4-dihydroxyphenylacetic acid (DOPAC), 5-hydroxyindoleacetic acid (5-HIAA) and homovanillic acid (HVA) in brain; 3-methoxy-4-hydroxyphenylglycol, DOPAC, 5-HIAA and HVA in cerebrospinal fluid; 5-HIAA, HVA and 5-HT in plasma; and 5-HIAA and HVA in urine. Alterations in chromatographic conditions, voltammetry and in vivo pharmacological manipulations are employed to verify the identity of the putative neurotransmitter and metabolite peaks in the biological samples.

Animals↗