Radioimmunoassay of cholecystokinin-pancreozymin

摘要: A sensitive and specific radioimmunoassay for cholecystokinin-pancreozymin (CCK-PZ) has been developed, using rabbit antisera to crude porcine hormone. Highly purified CCK-PZ, labelled with 131 I, repurified by column chromatography on Sephadex G15, was used as tracer. Separation of free from antibody-bound CCK-PZ carried out charcoal, ion-exchange resin, or a double antibody procedure. Non-specific interference the assay system serum factors abolished (as judged in-vitro in-vivo recovery studies) boiling diluting samples before assay. Ninety-nine per cent pure (standard), commercial preparations, caerulein, C-terminal 8- 12-amino acid fragments molecule, endogenous human all cross reacted in showed parallel inhibition curves. No significant reaction found gastrin, secretin, glucagon, insulin. The sensitivity is approximately 5 pg ml test solution, which proved adequate measuring physiological levels peripheral blood man. mean immunoreactive concentration 50 fasting normal subjects 60·4 ml. distribution individual values skewed, however, so that median much lower (30 ml). Older had higher than were young adults.