Background: The pancreatitis-associated protein (PAP) I and III, but not PAP II, mRNAs are constitutively expressed in the small intestine of rats.
Methods: We studied expression of both PAP I and PAP III mRNAs during development and on nutritional and hormonal manipulations.
Results: Between day 20 of gestation and day 21 of age, PAP mRNAs could barely be detected. Their concentrations increased dramatically from day 21 to day 45 of age and remained constant thereafter. Rats adapted to a diet with low carbohydrate content showed a significant decrease in PAP mRNA concentrations. Finally, whereas thyroidectomy and ovariectomy induced a decrease in both mRNA concentrations, and adrenalectomy a limited decrease in PAP III mRNA only, diabetes and castration did not alter the expression of either gene.
Conclusion: Gene expression of PAP I and III mRNAs is regulated in a coordinate manner in the rat small intestine during development and on nutritional and hormonal manipulations.