title: Substance P in the argentaffin carcinoid of the caecum: biochemical and biological characterization.
abstract: An argentaffin carcinoid tumour of the caecum which contained serotonin (167 micrograms/g) and consisted predominantly of EC1-cells, was analysed for the presence of peptides using immunohistochemical, biochemical and pharmacological methods. A very high content of 3.9 micrograms/g of immunoreactive substance P was found. The distribution of cells staining positively for substance P matched that of cells containing serotonin. While some immunoreactive somatostatin (3.2 ng/g) was present in the tumour, neurotensin, glucagon, gastrin, and motilin were not found. Part of the substance P immunoreactivity measured most likely represents authentic substance P: it behaved like substance P in two chromatographic systems and in two bioassays, and its activity on the guinea pig ileum was abolished by specific tachyphylaxis towards substance P.
mesh_terms: D002276:Carcinoid Tumor / Q000032:analysis*; D002430:Cecal Neoplasms / Q000032:analysis*; D005260:Female; D005455:Fluorescent Antibody Technique; D005755:Gastrins / Q000032:analysis; D005934:Glucagon / Q000032:analysis; D006801:Humans; D008875:Middle Aged; D009037:Motilin / Q000032:analysis; D009496:Neurotensin / Q000032:analysis; D012701:Serotonin / Q000032:analysis; D013004:Somatostatin / Q000032:analysis; D013373:Substance P / Q000032:analysis*
chemical_list: D005755:Gastrins; D012701:Serotonin; D013373:Substance P; D009496:Neurotensin; D013004:Somatostatin; D009037:Motilin; D005934:Glucagon