title: Gastrin-releasing peptide immunoreactivity in medullary thyroid carcinoma.
abstract: Two cases of gastrin releasing peptide (GRP)-producing medullary thyroid carcinoma are presented. Immunohistochemical examination revealed the presence of GRP-like immunoreactivity (IR-GRP) in the primary tumor tissues. High concentration of IR-GRP was also demonstrated in extracts of the primary tumors by radioimmunologic means with use of a GRP-specific antiserum. Chromatographic analysis showed that the immunoreactivity was composed of at least two molecular forms: one behaved as synthetic porcine GRP on Sephadex G-50 gel filtration and the other as porcine GRP (14-27), a C-terminal active fragment of GRP. The IR-GRP was shown not to be attributed to bombesin-like immunoreactivity. Substance P-like immunoreactivity was not detected in the tumor tissues by either immunohistochemical or radioimmunologic means. This is, as far as the authors are aware, the first finding of IR-GRP as an ectopic product in medullary carcinoma.
mesh_terms: D002116:Calcitonin / Q000378:metabolism; D002277:Carcinoma / Q000378:metabolism*; D002850:Chromatography, Gel; D005260:Female; D019886:Gastrin-Releasing Peptide; D006651:Histocytochemistry; D006801:Humans; D007158:Immunologic Techniques; D008875:Middle Aged; D010455:Peptides / Q000302:isolation & purification / Q000378:metabolism*; D011863:Radioimmunoassay; D013964:Thyroid Neoplasms / Q000378:metabolism*; D014020:Tissue Extracts / Q000032:analysis
chemical_list: D010455:Peptides; D014020:Tissue Extracts; D019886:Gastrin-Releasing Peptide; D002116:Calcitonin