VIP receptors on canine submucosal synaptosomes.
The present study characterized [125I]VIP binding to synaptosomes from the submucosa of canine small intestine. Studies of saturation, competition binding, and kinetic studies revealed high- and low-affinity binding sites. Studies with GTP-gamma-S and cholera toxin suggested that the receptor was coupled to a G-protein, possibly Gs. Competition with VIP analogs suggested that the N-terminal end of the molecule played the major role in determining affinity and that this receptor was for VIP, not PACAP. Cross-linking VIP to the receptor revealed a single peptide (M(r) congruent to 60,000). We suggest that VIP may act to modulate mediator release from enteric nerve endings.
Mao
Y K
YK
Division of Physiology and Pharmacology, McMaster University, Hamilton, Ontario, Canada.
Tougas
G
G
Barnett
W
W
Daniel
E E
EE
D000818:Animals; D001667:Binding, Competitive / Q000502:physiology; D002772:Cholera Toxin / Q000494:pharmacology; D004285:Dogs; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000494:pharmacology; D007413:Intestinal Mucosa / Q000294:innervation / Q000378:metabolism*; D007700:Kinetics; D008970:Molecular Weight; D011869:Radioligand Assay; D018005:Receptors, Vasoactive Intestinal Peptide / Q000378:metabolism*; D013574:Synaptosomes / Q000378:metabolism*
D018005:Receptors, Vasoactive Intestinal Peptide; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D002772:Cholera Toxin