AJP - Gastrointestinal and Liver Physiology, Vol 239, Issue 5 400-G405, Copyright © 1980 by American Physiological Society
Stimulation of pancreatic growth by intraduodenal amino acids and HCl
L. R. Johnson, S. J. Dudrick and P. D. Guthrie
Exogenous secretin and cholecystokinin (CCK) have been shown to stimulate
the growth of the exocrine pancreas. To conclude that a hormone produces an
effect under normal physiological conditions, one must demonstrate that the
endogenous hormone also produces the action in question. To release
endogenous secretin 0.01 N HCl was continuously infused into the duodenums
of eight rats for 5 days. Sixteen animals were prepared with catheters
inserted 1 cm below the pylorus. The other eight animals were infused with
PO4 buffer, pH 7.5. The infusion rate for both groups was 2 ml/h. Animals
were killed at the end of 5 days, and the oxyntic gland mucosa and pancreas
were examined. Pancreatic weights, DNA synthesis, DNa, RNA, and protein
content were significantly increased in rats receiving acid. An identical
experiment was set up to release endogenous CCK. In this experiment eight
rats received a solution containing 50 mM phenylalanine and 50 mM
tryptophan. The controls received the caloric equivalent in glucose. At the
end of 1 wk the pancreases of the rats infused with amino acids averaged
405 (P < 0.001) heavier than the controls. Similar increases occurred in
DNA, RNA, and protein content. These studies suggest that endogenous
secretin and CCK can be released in amounts sufficient to stimulate growth.
