Tissue-specific expression of the rat secretin precursor gene.

Secretin is a 27-amino acid gastrointestinal hormone that stimulates the secretion of bicarbonate-rich pancreatic fluid. We previously demonstrated that the secretin precursor gene is expressed in the brain as well as in the small intestine. In this study, we demonstrated that the abundance of secretin precursor mRNA in the heart, lung, and kidney was comparable to that of the small intestine. The nucleotide sequences of the coding regions of the secretin precursor mRNAs in these tissues were identical to those of the small intestine, indicating that secretin precursor proteins produced in these tissues are identical to those in the small intestine. This is the first report that the secretin precursor gene is also expressed in the heart, lung, kidney, and testis as well as in the gastrointestinal tract and brain.