Sexual dimorphism of pancreatic gene expression in normal mice.

A differential pancreatic behavior observed between male and female mice in diabetes and pancreatitis led us to study the gene and protein expressions of endocrine and exocrine pancreatic proteins in normal mice. We compared the levels of expression of six pancreatic genes and of four of the corresponding proteins in male and female mice OF1. Amylase gene expression was found to be significantly higher in females than in males, whereas trypsinogen and lipase gene expression were significantly lower. For chymotrypsinogen, reg, and insulin the differences were not significant. This sexual dimorphism did not exist in rat pancreas, where no gender difference was observed. After characterization of mice enzymes by sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and antibodies directed to the closely related human pancreatic enzymes, we have compared the levels of these proteins in mice pancreatic homogenates. No significant difference was observed between males and females at the level of protein expression. These data suggest a hormonal sexual difference in the regulation of pancreatic protein synthesis at the pre- and posttranscriptional levels in normal mice, which may play a role in the development of mice pancreatic diseases.