PANCREATIC REG PANCREATIC STONE PROTEIN (PSP) GENE-EXPRESSION DOES NOT CORRELATE WITH BETA-CELL GROWTH AND REGENERATION IN RATS/

The Reg/pancreatic stone protein (PSP) gene is postulated to be an imp ortant regulator of pancreatic beta-cell growth. To investigate this h ypothesis, we analysed the expression of the Reg/PSP gene following a 90% pancreatectomy and after chronic glucose infusion, two well-define d models of pancreatic beta-cell growth. There was a rapid induction o f the Reg/PSP gene in the remnant pancreas after a 90% pancreatectomy in rats during the period of marked growth of the exocrine and islet t issue. However, a similar rapid, but smaller, induction of the Reg/PSP gene was observed in sham-operated rats and in non-surgical control r ats in which there was no enhanced pancreatic growth. Furthermore, the re was no pancreatic Reg/PSP gene induction in a model of selective be ta-cell growth, the chronic glucose-infused rat. Thus, it is unlikely that: Reg/PSP is a beta-cell specific growth factor, even though the f unction of this important pancreatic gene is still unknown.