Abstract
Nitric oxide (NO) has recently been demonstrated to be a neurotransmitter in the non- adrenergic non-cholinergic (NANC) inhibitory nerve in the gastrointestinal tract. To clarify the significance of NO in patients with aganghonosis and hypoganglionosis, we investigated enteric nerve responses in colonic tissue. The samples were obtained from Hirschsprung's disease (HD) and its ailied disorders such as hypoganglionosis. Normoganglionic colon specimens were also obtained from 4 patients with HD and from 7 patients without constipation, and were used as controls. A mechanograph was used to evaluate in vitro colonic responses to electrical field stimulation (EPS) of enteric nervous systems. The graph was taken at before and after treatment with various autonomic nerve blockers, N^G -nitro-L-arginine (L-NNA) and L-argnine. Our results are as follows : (1) NANC inhibitory nerves were found to act on the normoganglionic colon and to act with a lesser extent in the hypoganglionic colon, but no action on the enteric nerves in the aganglionic colon. (2) NO mediates the relaxation reaction of NANC inhibitory nerve in the normoganglionic colon and reaction with lesser extent in the hypoganglionic colon, but none was observed in the aganglionic colon. Diminution and/or lack of action of NANC inhibitory nerve which is mediated by NO may be largely related to the impaired motility observed in patients with aganglionosis and hypoganglionosis.
