title: Sensitive radioimmunoassay for somatostatin using N-[125I]-Tyr-somatostatin as labelled antigen.
abstract: A sensitive radioimmunoassay for somatostatin using N-[125I]-Tyr-somatostatin is described and compared with that using [125I]-Tyr1-somatostatin. The minimum detectable amount of somatostatin using N-[125I]-Tyr-somatostatin as tracer was 0.1 to 0.5 pg, which is approximately 10-fold lower than the lower detection limit of the RIA using [125I]-Tyr1-somatostatin. Moreover, it was found that the shelf-life of N[125I]Tyr-somatostatin was prolonged in comparison with labelled Tyr1-somatostatin. Human pancreatic and gastric extracts displayed immunological similarity to synthetic somatostatin tetradecapeptide.
mesh_terms: D000818:Animals; D000941:Antigens; D004064:Digestive System / Q000032:analysis; D005260:Female; D006801:Humans; D007515:Islets of Langerhans / Q000032:analysis; D008297:Male; D010179:Pancreas / Q000032:analysis; D011863:Radioimmunoassay / Q000379:methods; D051381:Rats; D013004:Somatostatin / Q000031:analogs & derivatives / Q000032:analysis* / Q000276:immunology
chemical_list: D000941:Antigens; D013004:Somatostatin