Abstract

Background & Aims: Adenosine mediates somatic and visceral pain, but its effects on gut visceral nociception are unknown. Our aim was to test the hypothesis that adenosine alters oesophageal sensorimotor function.

Methods: In a double blind, randomized, placebo-controlled study, 14 healthy volunteers (M/F= 4/10) received either intravenous adenosine 100 μg/kg/min or placebo infusion. Prior to and during infusion, all subjects underwent stepwise graded oesophageal balloon distensions using impedance planimetry. Sensory responses and biomechanical properties were assessed and compared.

Results: Adenosine significantly lowered thresholds for first perception (median [IQR], cm H20; 10 [10] vs. 30 [10], p=0.007), discomfort (40 [10] vs. 50 [10], p=0.011), and pain (50 [20] vs. 70 [10], p=0.007) when compared to placebo. Also, the median threshold pressure required to induce first perception (p=0.017), discomfort (p=0.024), and pain (p=0.026) were lower when compared to baseline. The cross sectional area (CSA) of the oesophagus increased (p=0.032), and the circumferential wall tension/strain relationship shifted to the left (wall became stiffer) (p=0.043) after adenosine, when compared to baseline or placebo.

Conclusions: Adenosine can induce visceral hyperalgesia and decrease oesophageal distensibility in humans. These evoked-sensorimotor changes are similar to those described in patients with functional oesophageal (non-cardiac) chest pain. Thus, adenosine modulates oesophageal sensorimotor function and may play a role in the pathogenesis of functional chest pain.