Neurochemical basis of reflex relaxation in gastric corpus.

Three general propositions are set forth: (1) that different test meals delay gastric emptying by different mechanisms, so mixed meals of differing composition are likely to influence gastric emptying by characteristic constellations of mechanisms; (2) that a particular nutrient can delay gastric emptying by more than one pathway; and (3) that a given pathway can use more than one neurotransmitter. The progress made in recent years suggests that it should now be possible to characterize the chemical mediators activated by different nutrients to delay gastric emptying.