A modified method for the isolation and determination of brain histamine using Bio-Rex 70

Abstract

Bio-Rex 70, a weak cation exchange resin, has been used to specifically isolate histamine from rat brain tissue. This method compares favourably to other extraction procedures with respect to selectivity, reproducibility and time taken to perform the procedure. However, because it combines the optimum of these properties, it appears more adaptable for routine laboratory use. Following isolation, histamine is quantified fluorometrically after condensation with o-phthaldialdehyde (OPT). The sensitivity of the procedure allows for the chromatographic isolation, using Bio-Rex 70, of 12.5 ng histamine to give fluorescence twice that of blank. In addition, the use of Bio-Rex 70 enables the selective separation of histamine from fluorescent contaminants such as spermidine. The stability and the reproducibility of the adsorption and elution characteristics of Bio-Rex 70 enables the determination of 30 brain samples in a working day. This method has been applied to determine whole brain and regional brain levels of histamine in control and L-histidine-treated rats. The whole brain level of histamine, which was 50 ng/g, was increased by L-histidine and the highest concentration of histamine was found in the hypothalamus. Since the reliability of existing histamine extraction procedures is questionable, under certain conditions, it is suggested that the use of Bio-Rex 70 is a valuable addition in evaluating the possible physiological role of brain histamine.

The persisting (P) cell: histamine content, regulation by a T cell-derived factor, origin from a bone marrow precursor, and relationship to mast cells.

“…' P Cells Contain Histamine. We detected histamine in P cells, by using a sensitive and selective method (14), at levels of 24-210 ng/10' cells. The level of histamine measured by this technique in a population of resident peritoneal cells from (C57B1/6 x DBA/2)F1 hybrid mice was 330 ng/106 cells, corresponding to a level of7 tug/106 ofthe mast cells present.…”

“…Cells were suspended in 0.1 ml of phosphate-buffered saline and boiled for 10 min. Histamine was isolated and assayed spectrophotofluorometrically (14). The procedure was highly selective and sensitive for histamine.…”

ALTERATION IN THE LEVEL OF ENDOGENOUS HYPOTHALAMIC PROSTAGLANDINS INDUCED BY Δ9‐TETRAHYDROCANNABINOL IN THE RAT

“…For example, noradrenaline (Glowinski & Iversen, 1966) and histamine (Lewis, Fennessy, Laska & Taylor, 1980) have up to a 10 fold difference in the levels determined in the hypothalamus compared to the levels determined in the cerebellum. The wide distribution of prostaglandins without localized concentrations was first reported to occur in dog brain (Holmes & Horton, 1968).…”

Fluorometric determination of peripheral tissue histamine levels using Bio-Rex 70

“…Previous methods have often lacked specificity and have proved too laborious for routine use [9][10][11]. We have recently reported the use of the weak cation exchange resin Bio-Rex 70 in a column chromatographic extraction procedure for the isolation of brain histamine and its subsequent fluorometric quantification following condensation with o-phthaldialdehyde (OPT) [12]. This present study reports the modification of this method for application to the determination of peripheral tissue and fluid levels of histamine.…”

“…Although histamine condenses with OPT to produce a fluorophore of strong and stable fluorescence, OPT may form fluorophores with other compounds especially spermidine [13], L-histidine, carnosine (fl-alanyl-histidine) [ 14], histidyl-histidine [ 15], arginine [16] and 5-hydroxytryptamine [ 17]. Prealiminary studies have shown that L-histidine, arginine, carnosine, histidyl-histidine, homovanillic acid and 5-hydroxyindoleacetic acid do not bind to Bio-Rex 70 equilibrated in phosphate buffer at pH 7.5 (for discussion see LEwis et al [12]). Although the amines serotonin, noradrenaline and dopamine bind partially to Bio-Rex 70, these amines produce negligible fluorescence under the assay conditions which produce optimal his~ tamine fluorescence.…”