An automated fluorimetric assay for the simultaneous determinations of histamine and 5-hydroxytryptamine released from rat mast cell preparations.

An automated assay suitable for the extraction and simultaneous fluorimetric determination of histamine and 5-hydroxytryptamine (5-HT) released from rat isolated peritoneal mast cells is described. The method gave good reproducibility and accuracy in use and required a sample volume of 0.5 ml for assay at a sampling rate of 30/h. The system was evaluated by assessment of its performance in the determination of histamine and 5-HT released from rat mast cells in response to compound 48/80. The detection limit for the procedure was 2 ng 5-HT base/ml and 20 ng histamine base/ml.