PERIACINAR STELLATE SHAPED CELLS IN RAT PANCREAS - IDENTIFICATION, ISOLATION, AND CULTURE

Background-The pathogenesis of pancreatic fibrosis is unknown. In the liver, stellate cells (vitamin A storing cells) play a significant rol e in the development of fibrosis. Aims-To determine whether cells rese mbling hepatic stellate cells are present in rat pancreas, and if so, to compare their number with the number of stellate cells in the liver , and isolate and culture these cells from rat pancreas. Methods-Liver and pancreatic sections from chow fed rats were immunostained for des min, glial fibrillary acidic protein (GFAP), and alpha smooth muscle a ctin (alpha-SMA). Pancreatic stellate shaped cells were isolated using a Nycodenz gradient, cultured on plastic, and examined by phase contr ast and fluorescence microscopy, and by immunostaining for desmin, GFA P, and alpha-SMA. Results-In both liver and pancreatic sections, stell ate shaped cells were observed; these were positive for desmin and GFA P and negative for a-SMA. Pancreatic stellate shaped cells had a peria cinar distribution. They comprised 3.99% of all pancreatic cells; hepa tic stellate cells comprised 7.94% of all hepatic cells. The stellate shaped cells from rat pancreas grew readily in culture. Cells cultured for 24 hours had an angular appearance, contained lipid droplets mani festing positive vitamin A autofluorescence, and stained positively fo r desmin but negatively for alpha-SMA. At 48 hours, cells were positiv e for alpha-SMA. Conclusions-Cells resembling hepatic stellate cells a re present in rat pancreas in a number comparable with that of stellat e cells in the liver. These stellate shaped pancreatic cells can be is olated and cultured in vitro.