Radio-enzymatic determination of histamine: interference by fluoride and possible activation of histamine methyl transferase.
The reproducibility of a radio-enzymatic method for determining plasma histamine was found to be affected by the anti-coagulant used for collecting blood. Recovery experiments from whole blood indicated that heparin yielded values that were more accurate than with EDTA or sodium fluoride; fluoride gave a mean value which was +41% higher than with heparin (P=0.054). Addition of fluoride to a standard calibration curve, and of increasing amounts to aliquots of 5 ng histamine also yielded higher values than in controls, up to +15% (P<0.1) and +14.1% (P=0.03) respectively. Fluoride did not affect the detecting system and was not contaminated with histamine; nor did it breakdown the methyl donor, S-adenosyl-L-methionine. It is concluded that heparin is the anti-coagulant of choice and that fluoride may activate histamine methyl transferase from pig brain. Fluoride may possibly have a biological role as an enzyme-activator and a usefulness in the therapy of mastocytosis.
The Royal Liverpool University Hospital, UK.
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Bruce
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Taylor
D004492:Edetic Acid; D004789:Enzyme Activation; D005459:Fluorides; D006632:Histamine / Q000032:analysis*; D006637:Histamine N-Methyltransferase / Q000378:metabolism*; D006801:Humans; D015203:Reproducibility of Results
D006632:Histamine; D004492:Edetic Acid; D006637:Histamine N-Methyltransferase; D005459:Fluorides