GLUCOCORTICOID RECEPTOR GENE-EXPRESSION IN THE EXOCRINE AND ENDOCRINERAT PANCREAS

Although pleiotropic effects of glucocorticoids on the endocrine and e xocrine pancreas are well documented, it remains controversial whether these effects are due to direct interactions of glucocorticoid hormon es with their receptors in the respective target cells. We therefore e xamined gene expression of the glucocorticoid receptor (GR) in various functional compartments of the rat pancreas. Using in situ hybridizat ion by generating a radioactive cRNA probe from a specific cDNA clone for the rat glucocorticoid receptor we found a gradient in the express ion of receptor mRNA transcripts from endocrine > acinar > ductal cell s. In contrast, no specific hybridization signal was observed in the e ndothelial cells of vascular structures. Using a monospecific polyclon al antibody against the rat glucocorticoid receptor in Western blot an alyses we found significant expression of the 94 kD receptor protein i n an enriched pancreatic acinar cell preparation. This data suggest th at rat pancreatic exocrine cells might serve a direct target tissue fo r glucocorticoid action.