Monoclonal Antibodies to Somatostatin Receptor of Rat Brain

Abstract

Murine Monoclonal antibodies (MAbs) to the rat brain somatostatin (SRIF) receptor were produced. Sp 2/0 myeloma cells were fused with splenocytes of Balb/c mice immunized with the soluble rat brain SRIF receptor which was partially purified by gelfiltration chromatography. Screening by radioligand ([¹²⁵I-Tyr¹¹]SRIF-14) binding inhibition assay yielded three stable cell lines producing IgG1, IgM, or IgA antibody. Autoradiographic study of the polyacrylamide gel electrophoresed under nondenaturing conditions revealed that these MAbs inhibited the ligand binding to the receptor, regardless of their incubation with the receptor prior to the ligand binding. The results suggest that the MAbs produced are the antibodies to the ligand binding site of the receptor, and bind to the receptor in competition with the ligand.