Possible misinterpretations of radioimmunoassay results of endocrine tissues containing peptides in the micromolar range.

This paper describes the possible inhibition of labelled peptidic antigen antibody bindings of high affinity (affinity constant above 10(11) l/mol) by structurally non-related synthetic peptides according to their primary aminoacid sequence at concentrations of only 10(-6) mol/l i.e. approximatively 10(-3) g/l, in two radioimmunoassays. Such concentrations of peptides are present in 10% weight/volume suspension of various neuroendocrine and endocrine fresh tissues and may therefore be responsible for false positive results.