Deltins: immunochemical evidence for a novel population of peptides of the D cells of the gastro-entero-pancreatic endocrine system.

Differences between the immunocytochemical behaviour of antisera to partially purified porcine gastrins and antisera to either synthetic human gastrin-17-I or highly purified porcine gastrin-17-I raised the hypothesis that hog antral gastrin extracts contain peptides different from somatostatin and gastrin that are responsible for the immunocytochemical reaction of the former antisera in the D (delta) cells of the gastro-entero-pancreatic (GEP) endocrine system. This study was performed to prove this hypothesis. A discard fraction obtained after gel filtration of hog antral gastrin extracts on Sephadex G-50 Superfine was employed to immunize five rabbits.

Immunoradiometric and luminescence immunoenzymometric assay of human thyrotropin from dried blood spots for screening of neonatal hypothyroidism.

Two monoclonal antibodies to thyrotropin prepared in our laboratory were employed for the development of two-site immunometric assays in two modifications for the estimation of human thyrotropin in dried blood spots designed for the screening of neonatal hypothyroidism. The immunoradiometric assay using the second antibody labelled with 125I is simple and fast (one incubation step lasting 2 h). The detection limit of 1 mU/l and the absence of the hook effect up to a concentration of more than 1000 mU/l are optimal for neonatal screening; the presence of other glycoprotein hormones does not interfere with the assay.