Vasoactive intestinal polypeptide gene expression is characteristically higher in opossum gastrointestinal sphincters.
OBJECTIVE
Vasoactive intestinal polypeptide (VIP) has been suggested to be an inhibitory neurotransmitter in the sphincteric and nonsphincteric smooth muscles of the gut. However, the relative gene expression of VIP in these functionally diverse regions is not known.


METHODS
The gastrointestinal smooth muscle sphincters of opossums were excised from the adjoining nonsphincteric smooth muscles. RNAs were isolated and subjected to blot hybridizations with VIP complementary DNA probe. Relative expression of VIP gene was quantitated using the densitometric scanning of the VIP messenger RNA (mRNA) transcripts. The cellular specificity of VIP gene expression was investigated in cultures of neuroblastoma cells and myenteric plexuses and compared with those of the smooth muscle cells.


RESULTS
The data showed higher levels of VIP mRNA in the sphincteric than the adjoining nonsphincteric tissues. VIP mRNA were found in significantly higher amounts in the myenteric neurons and neuroblastoma cells than in the smooth muscle cells.


CONCLUSIONS
VIP gene expression was significantly higher in the sphincteric smooth muscle regions than in the nonsphincteric regions of the gut. The studies provide further evidence for the role of VIP in neurotransmission of the gut.
Bandyopadhyay
A
A
Department of Medicine, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania.
Chakder
S
S
Lynn
R B
RB
Rattan
S
S
D001003:Anal Canal / Q000294:innervation / Q000378:metabolism; D000818:Animals; D004068:Digestive System Physiological Phenomena; D004943:Esophagogastric Junction / Q000378:metabolism; D005260:Female; D015870:Gene Expression; D008297:Male; D009197:Myenteric Plexus / Q000166:cytology / Q000378:metabolism; D009447:Neuroblastoma / Q000378:metabolism / Q000473:pathology; D009474:Neurons / Q000378:metabolism; D009893:Opossums; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D009803:Sphincter of Oddi / Q000378:metabolism; D014018:Tissue Distribution; D014407:Tumor Cells, Cultured; D014660:Vasoactive Intestinal Peptide / Q000235:genetics*
D012333:RNA, Messenger; D014660:Vasoactive Intestinal Peptide