New hypothesis on the pathogenesis of ileocecal intussusception.
OBJECTIVE
Ileocecal intussusception is a relatively common surgical emergency in infants and young children. The etiology of intussusception is not clearly understood. Nitric oxide (NO) is a major inhibitory neurotransmitter in the enteric nervous system, which causes relaxation of the smooth muscles. In a lipopolysaccharide-induced experimental model of intussusception, altered intestinal motility is shown to be the result of increased NO released from various inflammatory mediators, which in turn leads to increased incidence of intussusception. The aim of this study was to examine the age-related changes in the nitrergic innervation of the ileocecal valve (ICV) to gain insights into the pathogenesis of intussusception.


METHODS
Whole-mount preparations of the myenteric plexus from the ileum, ICV, and proximal colon were stained using NADPH diaphorase histochemistry in newborn piglets (n = 3), 4-week-old (n = 3), 12-week-old (n = 3), and adult pigs (n = 3). Using light microscopy, the number of ganglia per square centimeter, the number of cells per ganglion, and the number of ganglion cells per square centimeter were determined.


RESULTS
There were striking regional and age-related differences in nitrergic innervation of myenteric plexus. Density of nitrergic neurons was significantly higher in the ICV than in the terminal ileum and proximal large bowel in the young animals (P < .001).


CONCLUSIONS
These findings suggest that the inflammatory reactions that usually precede intussusception may cause overproduction of NO by the nitrergically hyperinnervated ICV causing relaxation of the ICV and thereby facilitating ileocecal intussusception.
Cserni
Tamas
T
Children's Research Centre, Our Lady's Hospital for Children, University College Dublin, Dublin IZ, Ireland.
Paran
Sri
S
Puri
Prem
P
D000818:Animals; D003106:Colon / Q000294:innervation; D006651:Histocytochemistry; D007077:Ileal Diseases / Q000503:physiopathology; D007080:Ileocecal Valve / Q000294:innervation*; D007082:Ileum / Q000294:innervation; D007443:Intussusception / Q000503:physiopathology*; D009197:Myenteric Plexus / Q000737:chemistry / Q000166:cytology*; D018377:Neurotransmitter Agents / Q000032:analysis; D009569:Nitric Oxide / Q000032:analysis; D034421:Sus scrofa
D018377:Neurotransmitter Agents; D009569:Nitric Oxide