Abstract
A fluorometric method for the quantitative assay of vasopressin and oxytocin in individual rat pituitaries has been developed. Acid extracts of pituitaries are freed of amino acids and polyamines by passage over a copper-Sephadex column, and the peptides fraction is then labeled by reaction with fluorescamine. The resulting peptide fluorophors are separated by chromatography on a reverse-phase bonded column. Specificity of the procedure was ascertained by several criteria, including bioassay and amino-acid analysis of the eluted peptide fluorophors. The procedure serves as a model system for the assay of tissue peptides in the picomole range.