title: Concentration and in vivo synthesis of cholecystokinin in subcortical regions of the rat brain.
abstract: The in vivo biosynthesis of cholecystokinin (CCK) in subcortical regions of the rat brain was studied by intracisternal pulse injections of [35S]methionine. The rats were killed 1.0 or 1.5 h after the injection. Subcortical CCK extracted in boiling water and acetic acid was immunoabsorbed by an antiserum specific for the COOH-terminal sequence of CCK. Gel chromatography of the absorbed CCK separated four molecular forms with elution constants (Kav) of 0.08, 0.50 (corresponding to the tritriacontapeptide amide, CCK-33), 1.10 (corresponding to the COOH-terminal octapeptide, CCK-8), and 1.40 (a component which may correspond to the COOH-terminal tetrapeptide amide). Significant incorporation of [35S]methionine occurred in the largest (Kav approximately 0.08) and octapeptide-like form only. Chasing with methionine indicated a precursor relationship between the largest form and CCK-8. The results demonstrate a substantial synthesis of CCK also in subcortical regions of the brain.
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D002540:Cerebral Cortex / Q000378:metabolism; D002766:Cholecystokinin / Q000096:biosynthesis*; D002850:Chromatography, Gel; D006624:Hippocampus / Q000378:metabolism; D007163:Immunosorbent Techniques; D008297:Male; D008715:Methionine / Q000378:metabolism; D051381:Rats
chemical_list: D002766:Cholecystokinin; D008715:Methionine