Histamine formation from histidine

Amine build-up in fish muscle usually results from decarboxylation of amino acids in the muscle by enzymes of bacterial origin. This review will present information on the activity of bacterial decarboxylases and the formation of amines in fish. Mechanisms of decarboxylase action and production of bacterial decarboxylases in fish muscle are discussed. Emphasis is placed upon studies dealing with formation of histidine decarboxylase and histamine. Histamine, because of its involvement in Scombroid food poisoning, has been extensively studied with regard to its formation in fish and fishery products. 

Examples of amines that frequently occur in fish muscle include cadaverine from lysine, putrescine from ornithine and histamine from histidine. Histamine, because of its involvement in Scombroid food poisoning (histamine intoxication), has been extensively studied with respect to factors influencing its formation in many different fish species. Tuna and other fish from the families Scomberesocidae and Scombridae and a non-scombroid fish, mahi-mahi (dolphin fish) have been most... 

Histamine formation at 4°C was studied with resting cell suspensions of several histidine decarboxylating bacteria (Table III). Cells were harvested from cultures grown at 38°C in Trypticase soy broth (BBL, Cockeysville, MD.), suspended in 0.2 M phosphate buffer (pH 6.0) containing 0.1% histidine, and incubated anaerobically at 4°C for 21 days. After incubation, the cells were removed by filtration, and histamine was measured in the supernatant liquid. 

Several substituted histidines Table 4.8) have been tested as inhibitors of the histidine decarboxylase of guinea-pig kidney . From a consideration of the potencies of the substances tested, it was suggested that increasing the acidity of the nitrogens of the imidazole ring tended to produce stronger inhibitors. Similar studies on the inhibition of histamine formation by compounds related to DOPA or 5-HTP Table 4.8) showed that a-methyl-DOPA and DOPA are good inhibitors only the L-form of a-methyl-DOPA is an effective inhibitor of n-amino acid decarboxylase . The... 

Acetylcholine is formed from choline (which is also an important constituent of phospholipids) and acetyl CoA under the catalytic influence of choline acetyl-ase. It is hydrolised by acetylcholinesterase or choline esterase. Two important steps in the formation of noradrenaline from tyr dopa decarboxylase and dopamine hydroxylase. Adrenaline is formed from noradrenaline by phenyl ethanolamine A -methyltransferase. Both noradrenaline and adrenaline are metabolised by catechol 0-methyl transferase or monoamine oxidase. Some later steps in their metabolism involve aldehyde dehydrogenase and alcohol dehydrogenase (aldehyde reductase), After hydroxylation to its 5-hydroxy derivative, tryptophan is converted by 5-hydroxytryptophan decarboxylase to 5-hydroxytryptamine (serotonin). The major routes of serotonin metabolism involve either monoamine oxidase or hydroxyindole 0-methyltransferase. Histamine is synthesised from histidine by histidine decarboxylase, and is metabolised by either diamine oxidase or histamine Af-methyltransferase. Gamma aminobutyric acid is formed by glutamate decarboxylase and metabolised by... 

Because amine formation in fish muscle and other foods usually results from bacterial growth with concomitant production of a bacterial decarboxylase, this paper will concentrate on the mechanisms of bacterial decarboxylation and factors influencing the production and activity of the enzymes. Also, because of the overall scope of the subject, the availability of excellent reviews on bacterial decarboxylation (2, 3) and the public health importance of histamine in fish and fishery products, this paper will primarily be limited to a discussion of histidine decarboxylase (EC 4.1.1.22) and the formation of histamine in fish muscle. 

In solutions of histidine and histamine containing pyruvic acid, another reaction takes place (9) in addition to the formation of Schiff base. With increasing concentration of these amino acids apart from the formation of the wave of the Schiff base at a more positive potential, a decrease of the total limiting current can be observed (Fig. 5). The decrease corresponds to the formation of a polarographically inactive compound this may be interpreted by reaction (6) ... 

Leakage of metals from the column during elution can be the most significant problem due to their toxicity, but there are several ways to avoid this pitfall. Some references suggest the precaution of underloading IMAC columns (by as much as 20%) with the metal ion to begin with [8]. Another precaution is to add EDTA with imidazole, histidine, or histamine to the column fractions. EDTA competitively blocks formation of coordination complexes between protein... 

Figure 11.6. Formation of histamine and putrescine from the amino acids histidine and ornithine.

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