Distribution of vasoactive intestinal polypeptide and substance P receptors in human colon and small intestine

Abstract

Vasoactive intestinal polypeptide (VIP) and substance P are found in neurons in the lamina propria and submucosa and muscularis propria of human small intestine and colon. VIP receptors coupled to adenylate cyclase are present on epithelial, smooth muscle, and mononuclear cells. This study analyzes the distribution of [125I]VIP binding and [125I]substance P in human colon and small intestine using autoradiographic techniques. [125I]VIP binding was present in high density in the mucosal layer of colon and small intestine. [125I]VIP binding was not significantly greater than nonspecific binding in smooth muscle layers or the lymphoid follicles. In contrast, [125I]substance P binding was present in high density over the colonic muscle but was not present over the mucosal layer. In human colon cancer, [125I]VIP grain density over the malignant tissue was only slightly higher than background. These autoradiographic studies of [125I]VIP binding indicate that the highest density of VIP receptors was found in the small intestine and superficial colonic mucosa, whereas the density of substance P receptors was highest over the smooth muscle layers. These findings suggest a mismatch between immunochemical content of the peptide and autoradiographic density of the receptor.

Localization and characterization of neuropeptide receptors in human colon

“…Furthermore, we can confirm the previously reported high expression of bombesin receptors in the plexus and smooth muscle cells (Mantyh et al 1991), which we characterized here as the GRP subtype. We can also confirm the high expression of NK receptors in smooth cells and blood vessels (Korman et al 1989), characterized as NK 1 subtype in the present study.…”

“…For instance, we identified CCK-A in the myenteric plexus while this had not been seen before (Mantyh et al 1991) except for an incidental report in a colon cancer study (Reubi et al 1999a). While VIP receptors had been reported already in the human colonic mucosa and smooth muscles (Korman et al 1989;Mantyh et al 1991;Zimmerman et al 1989), we could identify PAC 1 expressed in the myenteric plexus and confirm therefore previous findings in rat and mice (Ekblad et al 1988). Moreover, we observed VPAC 2 expressed in the circular smooth muscle at the site where the interstitial cells of Cajal are known to be localized.…”

Duplicated receptors for VIP and PACAP (VPAC1R and PAC1R) in a teleost fish, Fugu rubripes

“…Surprisingly although VPAC 1 R has been detected in the gut of human, rat and goldfish (Sreedharan et al 1993, Usdin et al 1994, Chow 1997 it was absent in Fugu. This may merely reflect the position of the sample of Fugu gut collected, as VIP receptors have a differential distribution in this tissue (Sayadi et al 1988, Korman et al 1989. It should be noted that further overlap of tissue expression may occur between these six receptors, as the RT-PCRs were only carried out on single tissues from juvenile fish and developmental differences may also occur.…”

Expression of NK1 receptor at the protein and mRNA level in the porcine female reproductive system

“…NK1 receptor was found in the vascular endothelium of the human urinary bladder (Burcher et al 2000) and lungs (Mechiche et al 2003). NK1 receptor was also found in the muscular membranes of the canine stomach and intestines (Mantyh et al 1988), as well as human colon (Korman et al 1989). The presence of NK1 receptor in the mucosal epithelium of the oviduct and ovary is amazing, however this receptor was also described earlier in mucosal epithelium of the guinea pig colon (Burcher et al 1986) and rat trachea and bronchi (Ichikawa et al 1995).…”