Does the Third Pancreatic Hormone (APP) Play a Trophic Role in the Growth of the Embryonic Chick Proventriculus?

Summary

Avian pancreatic polypeptide (APP) is a recently discovered pancreatic peptide with hormone-like characteristics which acts as a gastric (proventricular) secretogogue in chickens. When injected into 12-14 day old fertile eggs, APP was shown to:

(a) cause a marked increase in proventricular protein/DNA ratio within two days, and (b) cause incorporation of labelled [¹⁴C] leucine into proventricular, but not into liver, protein unless very high doses were employed. The results suggests that APP may be an anabolic and secretogogic regulator of the developing avian gut.