The Role of Induced Phase 3 Contractions in the Control of Hunger and Food Intake

The role of induced phase 3 contractions in the control of hunger and food intake

1. Background In between meals the motor activity of the upper gastrointestinal tract is characterized by a cyclical pattern of contractions that consists of 3 phases: maximal contractile activity originating in the stomach and migrating down the small intestine (phase 3), followed by a phase of motor quiescence (phase 1) and a phase of progressively increasing motor activity (phase 2). In 1975 Itoh et. al. linked the phase 3 contractions of the migrating motor complex (MMC) to hunger sensations, by increasing the hunger sensations through exogenously administered motilin. The investigators previously demonstrated that phase 3 is associated with a 'hunger pang'. The trigger for the phase 3 initiation is unclear, but the gut hormones ghrelin and motilin are presumed to play a role. If either of these substances are administered intravenously, they induce a premature phase 3 in humans.

In previous studies, 'hunger pangs' could objectively be detected as peaks in subjective hunger ratings on a visual analog scale (VAS) using a custom made algorithm. A close association between phase 3 contractions of gastric origin and hunger peaks was observed and spontaneous food intake was also found to be associated with hunger peaks. By inducing phase 3 contractions through the administration of IV erythromycin, the time of food intake could be manipulated.

In a new study the investigators will evaluate if the food intake associated with the infusion of erythromycin is caused by the phase 3 contractions or by another yet unknown effect of erythromycin. To obtain this the investigators will use atropine, a muscarinic receptor antagonist, to inhibit the formation of contractions induced by a low dose of erythromycin. Since food intake is no longer a pure physiological act to still hunger sensations, it has obtained a social and emotional status in modern times where palatable food is abundant, the relationship of the subject towards food using multiple questionnaires will also be evaluated. 2. Aim To investigate whether contractions in the antrum are necessary to induce food intake with erythromycin or if erythromycin has a secondary effect to stimulate food intake. 3. Methodology 3.1. Subject selection Healthy volunteers will be recruited. See eligibility criteria for details

3.2. Questionnaires