Changes in vasoconstrictor and vasodilator neurotransmitters in nerves supplying arterioles in developing colorectal polyps.
OBJECTIVE
To examine the changes that occur in the immunohistochemistry of vasoconstrictor and vasodilator transmitters in nerves supplying early and advanced colorectal polyps.


METHODS
We studied the perivascular innervation of submucosal arterioles of colorectal polyps (n = 18) and the innervation of the epithelial layer of polyps compared to normal controls (n=8), using immunohistochemical markers for the neurotransmitters; noradrenaline (NA) (marker used; tyrosine hydroxylase (TH)), neuropeptide Y (NPY), vasoactive intestinal polypeptide (VIP), substance P (SP), and calcitonin gene-related polypeptide (CGRP). (Advanced polyps; villous adenomas>1.5 cm, polyps with severe dysplasia or partial carcinoma).


RESULTS
In submucosal arterioles there was a progressive decrease from controls through early polyps to advanced polyps in TH and NPY perivascular immunoreactivity (P<0.015 for both). VIP and SP immunoreactivity was higher in early polyps compared to controls, but markedly reduced in advanced polyps (P<0.05 for VIP). Sparse CGRP immunoreactivity was present in polyps only. Neural VIP and SP immunoreactivity in the lamina propria of polyp mucosa was more intense than in controls.


CONCLUSIONS
There is a decrease in vasoconstrictor neurotransmitters NPY and NA (shown by TH) around submucosal arterioles of both early and advanced polyps, but an increase in the vasodilator neurotransmitters, particularly VIP, in early colorectal polyps. These results suggest a predominantly vasodilatory neural influence in early polyps, perhaps indicating a mechanism that maintains polyp growth.
Chamary
V L
VL
Department of Surgery, Royal Free and University College Medical School, London, UK.
Loizidou
M
M
Boulos
P B
PB
Taylor
I
I
Burnstock
G
G
D000368:Aged; D001160:Arterioles / Q000276:immunology / Q000294:innervation*; D014408:Biomarkers, Tumor / Q000276:immunology; D015740:Calcitonin Gene-Related Peptide / Q000276:immunology; D003106:Colon / Q000098:blood supply* / Q000294:innervation; D003111:Colonic Polyps / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009478:Neuropeptide Y / Q000276:immunology; D009638:Norepinephrine / Q000276:immunology; D013373:Substance P / Q000276:immunology; D014446:Tyrosine 3-Monooxygenase / Q000276:immunology; D014660:Vasoactive Intestinal Peptide / Q000276:immunology
D014408:Biomarkers, Tumor; D009478:Neuropeptide Y; D013373:Substance P; D014660:Vasoactive Intestinal Peptide; D014446:Tyrosine 3-Monooxygenase; D015740:Calcitonin Gene-Related Peptide; D009638:Norepinephrine