The project on ontogeny of preprocholecystokinin and proenkephalin has been completed. The same cDNA probes have been used to study the regional distribution of preprocholecystokinin and proenkephalin mRNAs in rodent brain. The levels of prepocholecystokinin mRNA and cholecystokinin peptide were measured in several regions of rat and mouse brain using RNA blot analysis and radioimmunoassay. Comparison with proenkephalin mRNA levels in the same regions was made.
