Abstract: | The ability of essential and nonessential amino acids to stimulate the release of CCK was investigated in dogs using a bioassay procedure based on the perfusion of intestinal Thiry-Vella loops and determing the increase of pancreatic protein response as well as the potentiation of pancreatin bicarbonate secretion by a background doses of secretin (0.2 units/kg/h). All essential amino acids, except threonine, and all nonessential amino acids except cysteine were effective in CCK release when perfused in equimolar concentration (50-mM) through the intestinal loop. The peak pancreatic protein in response to tryptophan was about 89% of the maximal response to exogenous CCK in a dose of 25 units/kg/h. These data have also indicated that tryptophan and phenyloalanine are able to release small amounts of secretin. |