Role of non-adrenergic non-cholinergic inhibitory nerves in the colon of patients with ulcerative colitis

The cause of impaired colonic motility in patients with ulcerative colitis (UC) is unknown. The non-adrenergic non-cholinergic (NANC) inhibitory nervous system is one of the most important factors in the enteric nervous system of human gut. To assess the physiological significance of NANC inhibitory nerves in the colon of patients with UC, we investigated the enteric nerve responses of colonic tissues from patients with this disease. Colonic tissues were obtained from the lesional sigmoid colons of six patients with UC. Normal sigmoid colonic tissues obtained from ten patients with colonic cancer were used as controls. A mechanographic technique was used to evaluate in-vitro muscle responses to the electrical field stimulation (EFS) of adrenergic and cholinergic nerves before and after treatment with various autonomic nerve blockers. NANC inhibitory nerves were found to act on both normal colon and the lesional colon of patients with UC, but colon with UC was more strongly innervated by NANC inhibitory nerves than was the normal colon. These findings suggest that NANC inhibitory nerves play an important role in the impaired motility observed in the colon of patients with UC. Received Feb. 3, 1997; accepted May 23, 1997