Gastrogastric reflexes regulating gastric tone and their relationship to perception

Our aim was to investigate in humans the gastrogastric reflexes that regulate gastric tone and their relationship to perception. In nine healthy subjects, liquid distension (in 100-ml steps), warm stimuli (in 3 degrees C increments), and cold stimuli (in 6 degrees C decrements) were randomly applied in the stomach for 3 min at 8-min intervals. Gastric tone was measured as isobaric volume changes of air by a barostat, and perception was scored by a graded (0-6) questionnaire. Liquid accommodation produced an additional expansion of isobaric air maintained by the barostat (51 +/- 13 ml with 100 ml of liquid filling, P < 0.05), but this effect became inconsistent with further filling. An accommodation-like reflex was best evidenced by warm stimulation below the discomfort threshold (58 +/- 13 ml relaxation at 47 +/- 1 degrees C, P < 0.05). By contrast, cooling below discomfort induced a reflex contraction (-62 +/- 22 ml change at 18 +/- 2 degrees C, P < 0.05). In conclusion, gastric tone, i.e., accommodation and contraction, is modulated by a net of reflexes that arise from the proper wall of the stomach below the discomfort threshold.