Rapid and highly sensitive high-performance liquid chromatographic method for the determination of histamine and 3-methylhistamine in biological samples using fluorescamine as the derivatizing agent

New approach for the diagnosis of histamine intolerance based on the determination of histamine and methylhistamine in urine

Histamine intolerance is a disorder in the homeostasis of histamine due to a reduced intestinal degradation of this amine, mainly caused by diamine oxidase (DAO) enzyme deficiency, which provokes its accumulation in plasma and the appearance of adverse health affects. A new approach for the diagnosis of this intolerance could be the determination of histamine and its metabolites in urine. The aim of this work was to develop and validate a rapid method to determine histamine and methylhistamine in human urine by Ultra High Performance Liquid Chromatography and Fluorimetric detection (UHPLC-FL). The proposed method is a consistent procedure to determine histamine and methylhistamine in less than 11min with adequate linearity and sensitivity. Relative standard deviation was always lower than 5.5%, ensuring method precision; and mean recovery was greater than 99% for both analytes. The structure of histamine and methylhistamine conjugated with OPA were confirmed by UHPLC-ITD-FTMS which enabled to unequivocally identify both analytes in standards and also in urine samples. The analysis of histamine and methylhistamine in urine samples could be a potential new approach for the routine diagnosis of histamine intolerance, more patient-friendly and with clear advantages in terms of equipment and personnel demand for sample collection in comparison with current plasmatic DAO activity determination.

Simultaneous fluorometric measurement of histamine and tele-methylhistamine levels in rodent brain by high-performance liquid chromatography

An improved high-performance liquid chromatography (HPLC) method was developed for simultaneous analysis of histamine (HA) and tele-methylhistamine (tele-MHA) levels in mouse and rat brain. The method consists of a solid-phase extraction (SPE) and subsequent HPLC with postcolumn derivatization of the amines with o-phthalaldehyde. The recovery rates of HA and tele-MHA during the SPE procedure were 82.8+/-3.4 and 86.0+/-1.7%, respectively. The detection limits for HA and tele-MHA were 8 and 12pg, respectively, with sufficient linearity up to 30pg. Using this newly developed system, we observed that the brain tele-MHA levels in H3 receptor knockout mice were significantly higher than those of wild-type mice by 2.1-fold. Furthermore, we also observed that the brain HA and tele-MHA levels in Zucker rats were significantly lower than those of lean rats by 76.6+/-5.3 and 77.8+/-5.0%, respectively. These observations coincided well with those of previous studies using radioimmunoassay or HPLC with precolumn OPA derivatization, confirming the utilization of the assay system.

Determination of 4-amino-m-cresol and 5-amino-o-cresol by high performance liquid chromatography and fluorescence derivatization using fluorescamine

For the determination of two oxidation hair dyes, 4-amino-m-cresol (4-AC) and 5-amino-o-cresol (5-AC), a sensitive isocratic high performance liquid chromatography (HPLC) method using the reversed phase mode was developed. The hair dyes were pre-column derivatized with fluorescamine prior to injection. Sensitivity could be improved 10-fold for 4-AC and 50-fold for 5-AC by fluorescence detection compared to UV detection. The limit of detection was 1 ng/injection for 4-AC and 100 pg/injection for 5-AC, respectively. For the determination of both compounds in aqueous biological matrices in order to simulate conditions for penetration studies with pig skin, a solid phase extraction procedure using C18 cartridges and acetonitrile (ACN) for elution could be developed. Average recovery was 83.4% with a coefficient of variation (CV) of 2.64% for intra-day assay and 3.20% for inter-day assay for 5-AC and 2.89% and 3.41% for 4-AC, respectively.

Assay of histamine by nano-liquid chromatography/tandem mass spectrometry with a packed nanoelectrospray emitter

A nano-liquid chromatographic /tandem mass spectrometric (nanoHPLC/MS/MS) method has been developed for the sensitive determination of histamine, a vital neurotransmitter. The method involved pre-column derivatization of histamine with 7-fluoro-4-nitrobenzoxadiazole (NBD-F), thus increasing the hydrophobicity of the analyte and allowing it to be retained and stacked on a nanoelectrospay emitter packed with C18 reversed-phase particles. Sodium 1-heptanesulfonate, added as an ion-pairing reagent in the mobile phase for sample loading, was found to facilitate greatly the analyte retention. The packed nanoelectrospray emitter was easily prepared using fused-silica capillary of 75 microm i.d., and included creating an electrospray emitter tip and then slurry-packing a 5 cm long column with 5 microm silica-based particles. After sample loading, the mobile phase was changed for separation and a characteristic precursor-to-product ion transition, m/z 275 --> 258, was used for the quantification. A linear calibration curve in the range from 1.0-100 ng/mL histamine with an r2 value of 0.9995 was obtained. The detection limit was estimated to be 0.1 ng/mL histamine in water. In a preliminary validation, the method was applied to determine histamine in alcoholic beverages and rat brain tissues.

Novel Imidazole PVC-Based Sensor Based on a Thiopyrilium Compound

A novel imidazole membrane sensor based on 2,4,6-triphenyl thiopyrilium perchlorate (TTP) as an excellent charged carrier, poly(vinyl chloride) (PVC), the plasticizer dibutyl phthalate (DBP) and oleic acid as an additive is described. The sensor responds to imidazole over a wide concentration range from 1.0 x 10(-5) to 1.0 x 10(-1) M with a slope of +33.5 +/- 0.5 mV per decade. The detection limit of the electrode is 3.0 x 10(-6) M and it can be used for at least four weeks without any measurable change in sensitivity. The sensitivity of the electrode is high enough to permit the detection of as little as 0.2 microg/ml of imidazole without any significant interference from high levels of other components and especially, amino acids. The potentiometric selectivity coefficient data revealed negligible interference from common cations, anions and amino acids. The electrode has a relatively fast response time (<30 s), and good slope stability. The proposed sensor was successfully applied to the determination of imidazole in synthetic serum samples.

Assay and biological relevance of endogenous histamine and its metabolites: application of microseparation techniques

This review provides an overview of the assay methods used to determine the presence of endogenous histamine (HA) including its metabolites, and also discusses their biological significance. Firstly, this review briefly summarizes the biological significance of HA and its biological pathways. Next, the assay methods with microseparation techniques, such as gas-chromatography (GC), liquid-chromatography (LC), capillary electrophoresis (CE) and capillary electrochromatography (CEC) are looked at from a developmental viewpoint. Finally, the use of these methods, including flow cytometry techniques, for the determination of HA and its metabolites in biological samples, such as blood, urine, brain and cells, is described. The merits and demerits associated with each of these various methods are also discussed, along with their applications.

Polyamines as cancer markers: applicable separation methods

Spermine, spermidine, putrescine and cadaverine are aliphatic amines widely spread in the human body. Their concentrations together with their acetyl conjugates increase significantly in the biological fluids and the affected tissues of cancer patients. Their concentrations decrease with the improvement in the patient's condition on multiple therapy. Various chromatographic techniques are frequently used in monitoring concentrations of di- and polyamines in cancer. Among these techniques, thin-layer chromatography and liquid chromatography using pre- or postcolumn derivatization, separating on a reversed-phase or an ion-exchange column are the most commonly used. Besides, high-resolution capillary column gas chromatography (GC) is increasingly used over packed column GC, and in recent years, capillary zone electrophoresis has also gained some importance in polyamine determinations. The review examines the prospects and the limitations of polyamines as cancer markers using chromatographic and electrophoretic techniques.

Differential release of histamine and prostaglandin D2 in rat peritoneal mast cells: roles of cytosolic calcium and protein tyrosine kinases

We studied how the release of histamine and prostaglandin D2 (PGD2) were connected in stimulated rat peritoneal mast cells, and to what extent these processes were controlled by the cytosolic Ca2+ concentration, [Ca2+]i, and protein tyrosine kinases. In the presence of 1 mM CaCl2, the G-protein activating compound 48/80 (10 micrograms/ml) evoked a transient rise in [Ca2+]i and a relatively high secretion of histamine, but only a low release of PGD2. In contrast, 5 microM thapsigargin (an inhibitor of endomembrane Ca(2+)-ATPases) and 5 microM ionomycin evoked high and prolonged rises in [Ca2+]i, and stimulated the cells to release relatively small amounts of histamine and high amounts of PGD2. Stimulation of the cells with CaCl2 and 10 microM ATP4- gave only minor quantities of histamine and PGD2, despite of the micromolar level of [Ca2+]i reached. When CaCl2 was replaced by EGTA, rises in [Ca2+]i as well as release of histamine and PGD2 were reduced with each agonist, but the preference of agonists to release more histamine or PGD2 remained unchanged. In mast cells with depleted Ca2+ stores, the addition of CaCl2 stimulated the store-regulated Ca2+ entry resulting in a prolonged rise in [Ca2+]i. However, simultaneous addition of compound 48/80 and CaCl2 was required for release of histamine and PGD2. In cells with full stores, PGD2 release evoked by compound 48/80 was greatly reduced by genistein and methyl-2,5-dihydroxycinnamate, two structurally unrelated inhibitors of protein tyrosine kinases, whereas histamine secretion was not influenced by these inhibitors. Similarly, with thapsigargin or ionomycin as agonist, PGD2 release was more sensitive to the tyrosine kinase inhibitors than histamine secretion. We conclude that in activated rat peritoneal mast cells: (i) the influx of extracellular Ca2+ potentiates agonist-evoked rises in [Ca2+]i as well as histamine secretion and PGD2 release; (ii) the amplitude of the [Ca2+]i rise does not determine the preferential effect of agonists to release more histamine or more PGD2; (iii) the relatively high PGD2 release evoked by thapsigargin and ionomycin is probably due to their potency to evoke a prolonged rise in [Ca2+]i and to activate protein tyrosine kinases.

Simultaneous determination of histamine and serotonin in mast cells by high-performance liquid chromatography

A sensitive and rapid high-performance liquid chromatographic method for the simultaneous determination of histamine and 5-hydroxytryptamine (serotonin) in supernatants and cellular extracts from mouse bone marrow-derived mast cells was developed. The described method is based on a precolumn derivatization of histamine and serotonin with o-phthaldialdehyde (OPA) and subsequent separation of the amine-OPA adducts with an analytical reversed-phase C18 column combined with fluorometric detection (excitation wavelength 360 nm, emission at 455 nm). The mobile phase was 0.02 M sodiumacetate buffer (pH 8) including 5 mM 1-octanesulfonic acid and 50% methanol. The detection limits for histamine and serotonin were 3.3 pmol and 6.9 pmol, respectively (signal-to-noise ratio 2:1). The variations of peak areas of repeatedly injected low or high amounts of amine standards were 23.3% or 6.9% (for 0.5 ng or 12.5 ng histamine) and 26.4% or 4.0% (for 5.0 ng or 250 ng serotonin) during an experimental period of 4 weeks. The variation of retention times over 2 days was 1.1% for histamine and 1.7% for serotonin. A perfect linear relationship of amine concentrations and peak areas was documented by correlation coefficients of r > 0.999 for both histamine (0.1-125 ng) and serotonin (0.5-250 ng).