Differential symptomatic and electrogastrographic effects of distal and proximal human gastric distension

Abstract

Nausea and gastric dysrhythmias occur in conditions associated with gastric distension. The roles of distal and proximal gastric mechanoreceptors in these responses are unexplored. Because antral distension induces vomiting in animals and antral and fundic vagal afferent discharges differ, we hypothesized that distal gastric distension in humans leads to greater symptomatic and dysrhythmic responses than proximal distension. Symptoms and electrogastrograms were recorded in healthy humans during distal and proximal gastric distension with a barostat. Distal but not proximal distension induced nausea and a 747 ± 250% increase in dysrhythmic power ( P < 0.05), responses not affected by granisetron, indomethacin, or atropine, agents that block dysrhythmias in other settings. In the distal stomach, bloating and pain developed at lower pressures ( P < 0.05) not modified by granisetron, and compliance was significantly lower ( P < 0.05). In conclusion, gastric mechanoreceptor activation in the less-compliant distal stomach produces nausea and dysrhythmias via non-5-hydroxytryptamine3(5-HT3), non-prostaglandin-dependent, and noncholinergic pathways. Distal mechanoreceptor activation induces greater bloating and pain than proximal mechanoreceptor activation via 5-HT3-independent pathways.

Relationships Between Intragastric Food Maldistribution, Disturbances of Antral Contractility, and Symptoms in Functional Dyspepsia

“…Impaired proximal stomach accommodation to food has been consistently demonstrated in functional dyspepsia patients using different methods (3-5, 10, 11). On the other hand, antral tone and compliance have only recently been studied in humans (25,26) and an initial observation in patients with functional dyspepsia suggests that antral responses to either distension or duodenal infusion of nutrients were not significantly different from those obtained in healthy volunteers (26). Also, our data do not indicate an association between diminished proximal gastric retention of food and antral hypocontractility, which would presumably cause decreased resistance to food transfer from the proximal to the distal stomach.…”

Pathophysiology and treatment of functional dyspepsia

“…35,40 Recent studies indicate that not only the proximal stomach but also, and maybe more intensely, the distal stomach may be involved in symptom generation due to gastric distension. [41][42][43][44] …”

Drinking Capacity and Severity of Dyspeptic Symptoms During a Water Load Test After Nissen Fundoplication

“…In the absence of nutrients, other mechanisms that limit liquid ingestion in FD and post-Nissen symptomatic patients should be considered. Gastric and duodenal distension trigger vagovagal reflexes that result in proximal gastric relaxation and induction of satiety and fullness [30][31][32][33]. The vagovagal reflexes could also be activated during a drinking test with water [18].…”