The effect of stress on gastric emptying rate measured with a radionuclide tracer

Stress can delay gastric emptying rate. This phenomenon has not yet been investigated with a physiological solid test meal or a regional analysis.

We investigated the gastric emptying rate in beagle dogs using a radio-labeled solid test meal and a gamma camera. The transport to an unknown environment served as a stress stimulus. This offers the advantage to mimic fairly well the clinical situation just before a diagnostic or therapeutic procedure. Control values were obtained after the third investigation, in which all dogs were accustomed to the environment.

Regional analysis of the emptying curves from the whole gastric region revealed that the length of the lag phase increased with stress, but the post-initial emptying rate remained unchanged. Emptying of the fundus changed hardly, but the antropyloral motor activity decreased during stress.

Gastric emptying rate is impeded during stress. It is necessary to limit the unnatural stress-stimuli, in order to mimic the clinical situation. Measurement techniques that influence directly gastric emptying or act as a stress-stimulus by themselves are undesirable. A radionuclide solid test meal is preferable and a regional analysis reveals the impairment of the antral motility as the mechanism of the delay of gastric emptying.