Effect of phenylalanine on pancreatic amylase secretion in chicks (Gallus domesticus)

1. 1. Effect of phenylalanine (Phe) on pancreatic amylase secretion in growing chicks was investigated in four experiments. 2. 2. In Experiment 1, birds were injected through a wing vein with 0.25ml Phe at 0, 0.1, 0.5, 2.5 and 12.5mM in physiological saline. No significant difference was observed in amylase secretion among treatments. 3. 3. Effect of various concentrations of Phe with cholecystokinin (CCK, 0.31 Crick unit) on amylase secretion was investigated in Experiment 2. Amylase secretion increased with time, although no significant effect was detected in Phe treatment. 4. 4. Efficacy of Phe and tyrosine (Tyr) injection with CCK on amylase secretion was compared. There was no significant difference between Phe and Tyr treatments. 5. 5. Birds were injected intraperitoneally with dl-p-chlorophenylalanine (p-CP), which is an inhibitor of phenylalanine hydroxylase, or saline 1 day before the collection of pancreatic amylase in Experiment 4. Both chicks showed increased amylase secretion with CCK (0.31 Crick unit), whereas the response was at a drastically reduced rate in chicks with the p-CP treatment.