Figure 4. Effect of superfusion of the coeliac plexus with carboxy PTIO on the gastroduodenal inhibitory reflex.
A and B were obtained from the same preparation. Gastric distension performed while the coeliac plexus was superfused with L-arginine (5 × 10−4 M) triggered a significant (P≤ 0.001), long-lasting (16 min) decrease in the amplitude of duodenal contractions after a 1 min latency period (A). When the coeliac plexus was superfused with L-arginine (5 × 10−4 M) + carboxy PTIO (1.5 × 10−6 M), the inhibitory response was abolished and gastric distension elicited an excitatory response (B).