Oesophageal epithelial innervation in health and reflux oesophagitis.

BACKGROUND: The response of the oesophagus to refluxed gastric contents is likely to depend on intact neural mechanisms in the oesophageal mucosa. The epithelial innervation has not been systematically evaluated in health or reflux disease. AIMS: To study oesophageal epithelial innervation in controls, and also inflamed and non-inflamed mucosa in patients with reflux oesophagitis and healed oesophagitis. PATIENTS: Ten controls, nine patients with reflux oesophagitis, and five patients with healed oesophagitis. METHODS: Oesophageal epithelial biopsy specimens were obtained at endoscopy. The distribution of the neuronal marker protein gene product 9.5 (PGP), and the neuropeptides calcitonin gene related peptide (CGRP), neuropeptide Y (NPY), substance P (SP), and vasoactive intestinal peptide (VIP) were investigated by immunohistochemistry. Density of innervation was assessed by the proportion of papillae in each oesophageal epithelial biopsy specimen containing immunoreactive fibres (found in the subepithelium and epithelial papillae, but not penetrating the epithelium). RESULTS: The proportion of papillae positive for PGP immunoreactive nerve fibres was significantly increased in inflamed tissue when compared with controls, and non-inflamed and healed tissue. There was also a significant increase in VIP immunoreactive fibres within epithelial papillae. Other neuropeptides showed no proportional changes in inflammation. CONCLUSIONS: Epithelial biopsy specimens can be used to assess innervation in the oesophagus. The innervation of the oesophageal mucosa is not altered in non-inflamed tissue of patients with oesophagitis but alters in response to inflammation, where there is a selective increase (about three- to fourfold) in VIP containing nerves.

Chronic ethanol consumption affects cholinoceptor- and purinoceptor-mediated contractions of the isolated rat bladder.

Isolated bladder strips from 12-week ethanol-fed, pair-fed and control adult male rats were investigated. Contractile responses to carbachol (CCh; 0.1-300 microM) were statistically significantly potentiated in the ethanol-fed group compared to pair-fed and control. Contractions to beta,gamma-methylene ATP (beta,gamma-MeATP; 1-300 microM) were statistically significantly potentiated in the ethanol-fed group at the highest concentration tested (300 microM). Neurogenic contractions (0.5-32 pps) from the ethanol-fed group in the absence of atropine and after desensitisation by alpha,beta-methylene ATP (alpha,beta-MeATP; 3 microM), were significantly potentiated compared to the pair-fed and control groups; in the presence of atropine (1 microM), neurogenic contractions were significantly augmented at the higher frequencies. It is concluded that chronic ethanol treatment affects both cholinoceptor- and purinoceptor-mediated contractions of the rat bladder.