Receptors as Analytical Tools for Bioresponse-Linked Instrumental Analysis

Receptor assays for estrogenic and androgenic compounds are presented as examples for bioresponse-linked analyses as receptor affinities are generally related to the strength of pharmacological effects. Since mixtures of different ligands yield additive signals, receptor assays can be conveniently used for effect monitoring, especially for screening programs. A detection limit with an enzymelinked receptor assay (ELRA), based on the human estrogen receptor α, was achieved for 17-β-estradiol below 0.1 µg/l. A radioreceptor assay with the human androgen receptor reached a detection limit below 1 µg/1 for dihydrotestosterone. The hyphenation of receptor affinity extraction with LC/MS/MS techniques was demonstrated for estrogens. It is considered a first step in bioresponse-linked instrumental analysis.