TOPICAL GLYCERYL TRINITRATE RELAXES THE SPHINCTER OF ODDI

Background/Aim-Nitric oxide (NO) may be involved in non-adrenergic non cholinergic (NANC) inhibitory innnervation of the sphincter of Oddi (S O). The effects of topical application of glyceryl trinitrate (GTN), a NO donor, upon SO motility were examined. Methods-Nineteen patients u ndergoing routine SO manometry for investigation of abdominal pain wer e studied. After routine recording of SO motility, they were randomise d into three groups to receive 10 ml of normal saline, 5 mg GTN (0.5 m g/ml) or 10 mg (1 mg/ml) GTN. Drug solutions were infused topically on to papilla via the manometry catheter and recordings were continued fo r a further 5 minutes. Results-There was no significant change in SO m otor variables following application of normal saline. GTN reduced SO tonic and phasic contractions. In four patients, there was complete ab olition of all phasic contraction. Conclusions-Local application of GT N inhibits SO motility. This may have application for diagnostic and t herapeutic biliary endoscopy.