Influence of amino acids on gastric emptying in young pigs

The effects of amino acids on gastric emptying and secretion were studied in four young conscious pigs provided with a chronic gastric cannula. A basal test meal of 500 ml containing 10 g citrus pectin, 17.5 g sucrose, 100 mg phenol red alone or with glycine, L- or DL-tryptophan, DL-methionine or L-glutamic acid was poured into the stomach and recovered 20 min later. Glycine at concentrations of 26.7--106.8 mM/l did significantly affect gastric emptying, although at the highest concentration gastric emptying appeared to slow down. L-lysine (41.0 mM/l), DL-methionine (40.3 mM/l or L-tryptophan (29.4 mM/l did not significantly affect the rate of stomach emptying; L-tryptophan increased the amount of Cl- and H+ secreted as compared with the basal diet alone. The effects of addition of the essential amino acids, L-lysine and DL-methionine, were compared with those of the nonessential glycine and L-glutamic acid. There was no significant difference in the rate of gastric emptying or secretion between them. The L and DL isomers of lysine and trypotphan were not found to differ significantly in their effects on gastric emptying and secretion.