Distribution and heterogeneity of immunoreactive cholecystokinin (CCK) in the mucosa of the porcine gastrointestinal tract.
The concentration and molecular nature of cholecystokinin-like immunoreactivity (CCK-LI) in extracts of porcine intestinal mucosa were determined using sequence-specific radioimmunoassays. Highest CCK concentrations were measured in duodenal mucosa (258 +/- 60 pmol/g in the distal duodenum) followed by jejunal mucosa (204 +/- 36 pmol/g in the proximal jejunum) and pylorus (51 +/- 9 pmol/g). All other gastrointestinal regions proximal to the pylorus and distal to the jejunum contained less than 20 pmol/g. Pancreas contained less than 1 pmol/g. Gel chromatography in 6 M urea revealed four immunoreactive forms and this was confirmed by reverse-phase high-pressure liquid chromatography (HPLC). The predominant molecular form in acid extracts of duodenal mucosa resembled CCK-33 although high concentrations of the larger CCK form ('CCK-58') and of the form intermediate in size between CCK-33 and CCK-8 were measured. A molecular form resembling CCK-8 was the principal form in neutral extracts of the duodenum.
D000818:Animals; D000918:Antibody Specificity; D002766:Cholecystokinin / Q000276:immunology / Q000378:metabolism*; D004064:Digestive System / Q000378:metabolism*; D005753:Gastric Mucosa / Q000378:metabolism; D005755:Gastrins / Q000276:immunology; D007413:Intestinal Mucosa / Q000378:metabolism*; D008970:Molecular Weight; D010179:Pancreas / Q000378:metabolism; D011863:Radioimmunoassay; D013552:Swine
D005755:Gastrins; D002766:Cholecystokinin