Cell culture of the endocrine pancreas of the mouse in chemically defined media

Summary

Monolayer cultures of endocrine pancreatic cells from both fetal and postnatal mice have been established on a chemically defined medium, MPNL65/C, of high osmolality (340 mOsm). Precocious settling and attachment of fibroblastoid cells over the first 12 hr in vitro permitted the establishment, by decanting, of clusters of epithelioid cells in culture with very little fibroblastic contamination. Substituting high osmolality medium MPNL65/C at 36 hr of culture resulted in cytotoxic changes in contaminating fibroblasts within a few days; on the contrary, rapid cell outgrowth from the epithelioid clusters to form monolayers was not retarded. As determined by light microscopic observation of living and stained cultures, the pancreatic β cell was the major surviving cell species; no differentiated exocrine cells were detected; the question of other surviving endocrine cell types (α-1, α-2 cells) was not resolved. That the cultured β cells were endocrinologically competent was demonstrated by their synthesis and secretion of insulin. However, the levels of insulin secretion declined with increasing time in culture, and disruption of the monlayer due to unexplained causes was seen between the 3rd and 4th weeks in vitro. The murine monlayer cultures were unresponsive to glucose stimulation of insulin secretion, and in this way differed from primary pancreatic cell cultures of other mammalian species described by others.