title: Solid-phase radioimmunoassay for substance P.
abstract: The solid-phase immunoassay for quantification of substance P has been developed. The assay is based on the repartition of anti-substance P antibodies between the insoluble phase-immobilized substance P and the free peptide. The immobilized substance P-antibody complex is then quantified with 125I-protein A. The method allowed detection of 10 pg of substance P. The values of substance P concentration obtained by the present method in different regions of the rat brain were comparable to those obtained by standard radioimmunoassay with 125I-tyr-8-substance P as tracer. The described solid-phase radioimmunoassay is a simple, sensitive, and reliable technique for quantification of substance P-like immunoreactivity in biological samples.
mesh_terms: D000818:Animals; D000936:Antigen-Antibody Complex / Q000032:analysis; D001923:Brain Chemistry; D003429:Cross Reactions; D007700:Kinetics; D011817:Rabbits; D011863:Radioimmunoassay / Q000379:methods; D013373:Substance P / Q000032:analysis*
chemical_list: D000936:Antigen-Antibody Complex; D013373:Substance P