[Detection of gut hormone mRNAs by synthetic DNA probes in gut hormone producing tissues]

Synthetic DNA probes were tested as hybridization probes for detecting gut hormone mRNAs. When 4 gut hormones, including gastrin, somatostatin, gastrin-releasing peptide and calcitonin were examined, these probes were shown to be useful for mRNA detection in the tissues producing respective hormones. It was also revealed that there was a good correlation between the concentration of peptides determined by radioimmunoassay and the amounts of mRNAs. This methodology was applied for multiple gut hormone producing tumor with the aim to elucidate the mechanisms responsible for this phenomenon, and demonstrated that the tumor expressed a large amount of mature mRNAs encoding respective hormones. These results indicate that increase of mRNA production is one of the mechanism responsible for multiple gut hormones production by tumor.