Regulation of the enteric nervous system in the colon of patients with slow transit constipation

Abstract

Background/aims: The cause of impaired motility in patients with slow transit constipation is unknown. To clarify the physiological significance of cholinergic, adrenergic, non-adrenergic non-cholinergic inhibitory nerves in the colon of patients with slow transit constipation, we investigated the enteric nerve responses on lesional and normal bowel segments derived from patients with slow transit constipation and patients who underwent colon resection for colonic cancers.

Methodology: Twenty preparations were taken from the lesional colon of 6 patients with slow transit constipation (2 men and 4 women, aged 23 to 68 years, with a mean age of 44.0 years). Thirty-six preparations were taken from the normal colon of 12 patients with colonic cancer (6 men and 6 women, aged 40 to 60 years, with a mean age of 52.2 years). A mechanographic technique was used to evaluate in vitro muscle responses to acetylcholine, adrenalin, electrical field stimulation of adrenergic and cholinergic nerves before and after treatment with various autonomic nerve blockers.

Results: The contraction reaction to acetylcholine in the colon with slow transit constipation was significantly weaker than in the normal colon (P < 0.01). The relaxation reaction to adrenalin in the colon with slow transit constipation was stronger than in the normal colon. The colon with slow transit constipation was more strongly innervated by non-adrenergic non-cholinergic inhibitory nerves than the normal colon, significantly (P < 0.05).

Conclusions: These findings suggest that a decrease of cholinergic nerve and an increase of non-adrenergic non-cholinergic inhibitory nerve play an important role in the impaired motility observed in the colon of patients with slow transit constipation.