Vasopressin Receptor mRNA Expression in the Human Gastrointestinal Tract

BACKGROUND/AIM: Vasopressin and oxytocin are closely related peptides, and both exert effects on the gastrointestinal function. In the present study, we wanted to map the expression of vasopressin receptor mRNAs (V1a, V1b/V3, and V2) in nontumorous tissue biopsy specimens of human gastrointestinal tract and surrounding tissues. METHODS: Total and polyA+ RNAs were isolated from human tissue biopsy specimens using an automated nucleic acid extractor and, subsequently, converted into single-stranded cDNA. Semi-nested PCR amplifications were carried out, using gene-specific V1a, V1b/V3, and V2 receptor primers. The PCR amplicons were partially sequenced to confirm their identity. RESULTS: The present study demonstrated the expression of vasopressin receptor mRNAs in human gastrointestinal tract, pancreas, kidney, lung, brain, and ovary. The expression pattern varied between different parts of the gastrointestinal tract. In the colon ascendens, V1a receptor mRNA expression could not be detected in 3 out of 4 analyzed tissue biopsy specimens. On the other hand, all the vasopressin receptor mRNAs were expressed in all colon transversum biopsy samples. CONCLUSIONS: V1a, V1b/V3, and V2 receptor mRNAs are widely expressed throughout human gastrointestinal tract and surrounding tissues. The data obtained provide information for further mapping and determination of the physiological role of the vasopressin receptor mRNA expression in normal and tumorous tissues.