Pancreatic regeneration caused by ethionine in the guinea pig

Hartley strain guinea pigs were given 10 daily intraperitoneal injections of either ethionine (0.01, 0.04, or 0.07 g/kg body weight) or methionine (0.08, 0.25, or 0.5 g/kg body weight) while on a protein free diet. From day 11, they were fed a protein sufficient diet. The highest doses of either ethionine or methionine caused 80% mortality. At better tolerated doses, focal pancreatic necrosis followed by regeneration was induced by ethionine but not by methionine. Ethionine caused nucleolar fragmentation, an increase in free ribosomes, and focal cytoplasmic degradation, all of which were reversed by 30 days. Regeneration of pancreatic acinar cells and pancreatic duct cells was assessed at 10,12,16, and 30 days from the start of the experiment by counting either metaphases arrested by colchicine or nuclei labeled by ³H thymidine in autoradiograms. Ethionine caused maximal regeneration of acinar cells at 16 days. No significant regeneration of duct cells was detected on those days monitored.