Study on the specificity of Shore's method for the determination of histamine in various tissues.

Specificity of Shore's method for the histamine determination was investigated by examining the fluorescence spectrum of the extract from rat gastric mucosa, biopsy specimen of human gastric mucosa, human gastric juice and human whole blood. An almost identical spectrum to that of pure histamine was obtained with the extract from rat gastric mucosa and human whole blood, whereas the spectrum with the extract of human gastric biopsy specimen and human gastric juice was different from that of histamine. By means of high-performance liquid chromatography, an approximately three times more concentrated extract from human gastric mucosa gave a distinct peak of histamine while a hundred times concentrated gastric juice gave no measurable peak of histamine. Fluorescence spectrum of the substances which might be extracted with histamine was examined. The ratio of the fluorescence of histidine to that of equimolar concentration of histamine at the wave length for histamine determination was 4.62%. From the above results, it has been concluded that Shore's method is useful for the determination of histamine contents in the gastric mucosa and whole blood if approximately 5% contamination with histidine is taken into consideration.