Modifications of gastric compliance in dogs related to changes of extracellular fluid volume: a possible physiological role.

Gastric compliance was measured with an intragastric probe connected to a water manometer in pylorus-ligated anesthetized dogs. Measurements were carried out in the same animal at different levels of extracellular fluid (ECF) obtained by expansion, bleeding and reexpansion. Acute isotonic expansion of the ECF volume shifted gastric compliance curves upwards and to the left, indicating that the stomach retains less volume than the control at the same intraluminal pressure. Conversely, the acute loss of blood shifted gastric compliance curves downwards and to the right. The data suggest that the ECF volume contributes to the modulation of gastric compliance.