DEVELOPMENTAL, NUTRITIONAL, AND HORMONAL-REGULATION OF THE PANCREATITIS-ASSOCIATED PROTEIN-I AND PROTEIN-III GENE-EXPRESSION IN THE RAT SMALL-INTESTINE

Background: The pancreatitis-associated protein (PAP) I and III, but n ot PAP II, mRNAs are constitutively expressed in the small. intestine of rats. Methods: We studied expression of both PAP I and PAP III mRNA s during development and on nutritional and hormonal manipulations. Re sults: Between day 20 of gestation and day 21 of age, PAP mRNAs could barely be detected. Their concentrations increased dramatically from d ay 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 ovariec tomy 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 o f PAP I and III mRNAs is regulated in a coordinate manner in the rat s mall intestine during development and on nutritional and hormonal mani pulations.