Monoclonal antibodies to the nonpeptide angiotensin II receptor antagonist, losartan.

ABSTRACT

Two murine monoclonal antibodies were produced to losartan (DuP 753), a nonpeptide angiotensin II receptor antagonist. Using a solid phase competitive enzyme-linked immunosorbent assay (ELISA), each antibody was examined for its ability to bind to a set of losartan analogs that differ structurally in varying degrees. Both antibodies distinguished fine structural changes in the analogs, particularly at the R5 position of the imidazole ring. No cross-reactivity towards either antibody was observed with the natural ligand angiotensin II, the peptide antagonist saralasin, or the AT2 selective nonpeptide antagonist PD123177.