Effect of pentagastrin on rabbit stomach and small intestinal protein synthesis

In an vitro organ culture system, we studied the effects of pentagastrin on rabbit fundic mucosa and small intestinal protein synthesis. The incorporation of [14C]leucine into protein was measured after 24 hr of incubation at 37 degrees C in a 95% oxygen-5% CO2 atmosphere. Biopsies were taken from the stomach, duodenum, jejunum, and ileum of rabbits fasted for 64 hr. Pentagastrin (0.5 microgram/ml) significantly increased protein synthesis in stomach explants at the 24-hr period but did not significantly increase protein synthesis in the duodenum, jejunum, or ileum explants. The results of these in vitro experiments may indicate that pentagastrin is not trophic for rabbit small intestine or, in contrast to its direct effect on the fundic mucosa, pentagastrin acts indirectly in the previously noted in vivo stimulation of intestinal protein synthesis.