Oxytocin and oxytocin-receptor mRNA expression in the human gastrointestinal tract: a polymerase chain reaction study.
OBJECTIVE
Oxytocin (OT) has a wide range of effects throughout the body. However, the role of OT on the gastrointestinal (GI) tract has to be settled. So far, the few studies performed reveal no conclusive results. The aim of this study was to examine the expression of OT and OT-receptor mRNA in the human GI tract.


METHODS
Full-thickness biopsies from all segments of the GI tract and the gallbladder were collected during operations at the Department of Surgery, Malmö University Hospital. Biopsies were taken and put immediately into fluid nitrogen and stored at -70 degrees C until total RNA was extracted after mechanical tissue homogenization. Subsequently, poly A(+) mRNA was isolated from the total RNA extract using an automated nucleic acid extractor and converted into single-stranded cDNA. PCR amplifications were carried out using gene-specific OT and OT-receptor primers. The specificity of the PCR amplicons was further confirmed by Southern blot analyses using gene specific OT and OT-receptor hybridization probes.


RESULTS
Expression of OT and OT-receptor mRNA was detected in nearly all segments of the GI tract analyzed. In most of the biopsy specimens analyzed, co-expression of both OT and OT-receptor mRNA appeared to take place.


CONCLUSIONS
The present study demonstrates that OT and OT-receptor mRNAs are expressed throughout the GI tract. A possible physiological and/or pathophysiological role of OT and OT-receptor expression in the human GI tract and the cellular location of its expression remain to be shown.
Monstein
Hans-Jürg
HJ
Molecular Biology Laboratory-LMO, Strategic Development, University Hospital, S-581 85 Linköping, Sweden.
Grahn
Niclas
N
Truedsson
Mikael
M
Ohlsson
Bodil
B
D000199:Actins / Q000378:metabolism; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D015139:Blotting, Southern; D017931:DNA Primers / Q000737:chemistry; D018076:DNA, Complementary / Q000378:metabolism; D004277:DNA, Single-Stranded / Q000737:chemistry; D005260:Female; D041981:Gastrointestinal Tract / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009584:Nitrogen / Q000378:metabolism; D009693:Nucleic Acid Hybridization; D010121:Oxytocin / Q000096:biosynthesis*; D016133:Polymerase Chain Reaction / Q000379:methods*; D012313:RNA / Q000737:chemistry / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D018045:Receptors, Oxytocin / Q000096:biosynthesis*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D000199:Actins; D017931:DNA Primers; D018076:DNA, Complementary; D004277:DNA, Single-Stranded; D012333:RNA, Messenger; D018045:Receptors, Oxytocin; D010121:Oxytocin; D012313:RNA; D009584:Nitrogen