1985 Volume 82 Issue 2 Pages 277-287
A sensitive and specific radioimmunoassay of cholecystokinin (CCK) has been achieved by method of Chang and Chey. Natural porcine CCK33 was iodinated by a modification of chloramine-T method. Purification and separation of labelled CCK was carried out by two-step procedure incorporating gel filtration and ion-exchange chromatography. The labelled preparation has a specific radioactivity of 709mCi/μM. Nonspecific plasma interference was eliminated by a XAD-2 resin column extraction technique. High recovery of CCK has resulted from this procedure for extraction.
The contribution of gastrin was relatively small in extracted samples. The detection limit was 3.2pM. Intra- and interassay precision was 27.0±2.4 (M±SD) pM(n=10) and 32.4±4.0 pM (n=10), respectively. Using this assay, plasma CCK concentrations in response to ingestion of a test meal were studied in 6 healthy subjects. After ingestion of a meal, the mean plasma CCK concentration increased significantly above the fasting concentration of 11.6±0.5 (M±SE) pM and remained elevated over a 2-hr period (p<0.01). In 6 healthy subjects, Meltzer-Lyon test was studied. As the flow of bile from duodenal tube increased markedly following intraduodenal ingestion of 25% MgSO4 40ml, significant increase in plasma CCK concentration was detected (p<0.05).
Nippon Shokakibyo Gakkai Zasshi
Nippon Shokakibyo Gakkai Zasshi Kou
