Cholecystokinin peptides and receptor binding in Alzheimer's disease.

Cholecystokinin (CCK) is a peptide that can be found in the cerebral cortex in high concentrations and is involved in learning and memory as well as neurodegenerative processes. Cortical brain samples from 9 patients with Alzheimer's disease and 9 matched control cases were studied with respect to the concentrations of various molecular forms of CCK and the CCK receptor binding characteristics. No differences were found between patients and controls in any of these measures. Significant correlations were found between the concentrations of CCK-8 sulphated and the three nonsulphated CCK peptides measured. In addition, the concentrations of CCK-4 and CCK-5 showed a highly significant and positive correlation.