Abstract

Motilin is found in the upper intestine of pig and man and in man is released by acid. A similar release by acid has now been found in the pig and is associated with markedly reduced immunostainable motilin in the upper small intestine. Clamping the arteries and veins to the stimulated segment immediately reversed the rise of plasma motilin, indicating the motilin release to be an entirely local phenomenon. The apparent half life of endogenous motilin was 3.9 minutes. No release of motilin was seen after a meal and the possible physiological role of motilin thus remains speculative.