DYSPLASTIC NITRERGIC NEURONS IN THE RECTUM OF A PATIENT WITH RECTAL ECTASIA

We present a histochemical study of resected colon from a 13-year-old boy diagnosed with rectal ectasia. Laminar preparations and sectioned tissue of rectum were assayed histochemically for nitric oxide (NO) sy nthase activity by reducing nitro blue tetrazolium salt in the presenc e of the cofactor NADPH. Tissue preparations displayed intensely label led neurons and fibers throughout the gut wall. Laminar preparations o f Meissner's plexus showed a hyperplasia of ganglia and NO-related neu rons throughout the length of the resected rectum compared with normal bowel. Sectioned tissue of the Auerbach's plexus demonstrated a norma l number of ganglia and NO-related neurons. As well, the ectatic bowel showed a proliferation of nerve fibers in keeping with the degree of circular smooth muscle hypertrophy. This proliferation may represent a reactive phenomenon secondary to the functional obstruction. The NO h istochemical technique may form the basis of further investigations in defining the cause of this functional obstruction. Copyright (C) 1997 by W.B. Saunders Company.