Possible Interaction: Cholecystokinin and Phenylalanine

“Basal levels of CCK were 1.10 +/- 0.12 pmol/L; 20 minutes after L-PA, CCK levels increased to 5.49 +/- 0.83 pmol/L. There was no increase in CCK following D-PA or placebo.”

“Release of CCK by L-PA is associated with a reduction in subsequent food intake, and this suggests that CCK is an important satiety hormone in humans.”

“At more than 20 mm, Phe induced dose‐dependent CCK secretion and intracellular Ca2+ mobilization in STC‐1 cells.”

“In the presence of 3.0 mm extracellular Ca2+, 10 and 20 mm Phe induced significantly higher CCK secretion than under normal conditions (1.2 mm extracellular Ca2+).”

“ Intraluminal l‐phenylalanine (Phe) stimulates cholecystokinin (CCK) secretion in vivo and in vitro.”

“In conclusion, our observations indicate that the energy intake-suppressant effect of phenylalanine is related to the stimulation of CCK and PYY, while the glucoregulatory effect may be independent of stimulation of plasma GLP-1 or slowing of gastric emptying.”

“In humans, phenylalanine stimulates plasma cholecystokinin (CCK) and pyloric pressures, both of which are important in the regulation of energy intake and gastric emptying.”

“l-phenylalanine Phe ) has been shown to elicit release of the gut hormone cholecystokinin (CCK) and reduce energy intake.”

“Immunoreactive cholecystokinin was significantly stimulated to 9.4±1.4pmol/l only by intraduodenal phenylalanine.”

“… -phenylalanine (… cholecystokinin (CCK) plasma concentrations and duodenal bile salt output (p less than 0.005) as compared with a control electrolyte solution, but did not change … mmol), isoleucine (21.5 mmol), lysine (31 mmol), threonine (23 mmol) - did not change CCK plasma concentrations, bile salt or pancreatic enzyme output.”

“In contrast, intraduodenal perfusion of phenylalanine (10 mM) produced a significant increase in plasma CCK levels (6.7 +/- 0.8 pM) and a three- to fourfold increase in pancreatic enzyme outputs.”

“ Phenylalanine increased the concentrations of plasma insulin, cholecystokinin , and pancreatic DNA (mg/g) and the expression of trypsin gene but decreased the pancreatic protein:DNA ratio and tended to decrease the pancreas weight (g/kg of BW).”

“Administration of phenylalanine inhibited basal K(+) channel activity and caused CCK cell depolarization, consistent with changes necessary for hormone secretion.”

“ Phenylalanine and tryptophan stimulated CCK release from intestinal CCK cells, and this stimulation was also blocked by CaSR inhibition.”

“Additionally, CCK secretion by an isolated I cell population was increased by 30 and 62% in response to L-Phe in the presence of physiological (1.26 mM) and superphysiological (2.5 mM) extracellular calcium concentrations, respectively.”