Cytotoxic effects of alloxan treatment in vitro on monolayer cultures of neonatal rat pancreas

K. C. Gorray, D. G. Baskin and W. Y. Fujimoto Monolayer cultures of neonatal rat pancreas were exposed briefly (5 min) to alloxan and were then maintained for several days (up to 14 days) to examine the long-term effects of alloxan exposure on B cells. Alloxan (0-10 mM) caused a dose-dependent reduction in rates of insulin release during the first 24 h after treatment. This reduction persisted throughout the period of observation. Rates of glucagon release were unaltered by all concentrations of alloxan tested. Spontaneously decomposed alloxan had little or no effect on rates of insulin release. The simultaneous presence of high concentrations of glucose during exposure of cells to alloxan exerted a rapid protective effect against alloxan toxicity that was both glucose and alloxan dose dependent. Alloxan treatment of pancreatic monolayer cultures may allow for a comparison of those actions of alloxan that are directly on and specific for islet B cells. Furthermore, alloxan-treated cultures may represent a unique in vitro system for studying the physiology and biochemistry of other islet cell types in cultures in which B cells and insulin are reduced, as well as for studying glucose interactions with the B cell.