Effects of some physiologic substances on gastrointestinal propulsion in the rat

¹ Department of Pharmacology, Research Division, Mead Johnson and Company, Evansville, Indiana

The influence of some physiologic substances on the distribution of a dye following oral administration in the rat has been studied by a very sensitive and discriminative technique. Under certain conditions an agent may influence the rate of movement through one portion of the gastrointestinal tract while not affecting the transit through an adjacent segment. Propulsive motility was slowed following subcutaneous administration of l-epinephrine, l-norepinephrine, glucagon, 5-hydroxytryptamine, or 5-hydroxytryptophan. The characteristics of the inhibition produced by each agent were not the same. Insulin inhibited the motility of the gastrointestinal tract 15 minutes following subcutaneous administration, but 45 minutes after administration there was intense stimulation of propulsion. Ganglionic blockade eliminated the stimulating effect of insulin on the intestine but only partially reduced the stimulation of the stomach.