[Titration method for determination of carcinine (beta-alanyl-histamine). Application to the heart of Carcinus maenas...

1.--Carcinine was isolated by ion-exchange chromatography and titrated spectrophotometrically. The technique used was based on formation of an azo derivative of carcinine with sulfanilamide at basic pH. It allowed detection of carcinine at 1 microgram/ml concentration. 2.--Histamine could be detected simultaneously with the same technique, provided its concentration was greater than 1 microgram/ml. 3.--The mean amount of carcinine in cardiac tissues of Carcinus maenas was 22.1 micrograms/ml dry cardiac tissue. 4.--The technique described above did not allow detection of histamine in the heart of Carcinus maenas. If present, histamine must be at a concentration smaller than 0.1 microgram/ml dry cardiac tissue.