抄録
This report deals with responses of vagal afferents to amino acidsin the gut. To observe the effects of infusion of amino acids solutions into thestomach or intestine, afferent nerve activities were recorded fromperipheral cut end of gastric or celiac branch of the vagus nerve in anesthetized rats. Isotonic (150 mM) solution of 8 essential and 10 non-essential aminoacids (1 ml) were slowly infused.Reults: Infusion of MSG solution into the stomach evoked an activationof vagal gastric afferents, however, infusions of other 17 amino acidsolutons and saline evoked no siginificant response. Infusion of most of amino acid solutions including essential and non-essential aminoacidsinto the intestinal canal evoked the excitatory afferent response in celiac branch of the vagus nerve, and four amino acids, methionine,threonine, glycine and histidine evoked inhibitory response. These observations suggest that gastric MSG sensor works as an proteinmarker and intestinal amino acid sensors send their infomation tothe brain through vagal afferents which may play a role in appetiteand proein metabolism. [J Physiol Sci. 2008;58 Suppl:S27]
