Exposure to binge ethanol and fatty acid ethyl esters exacerbates chronic ethanol-induced pancreatic injury in hepatic alcohol dehydrogenase deficient deer mice

Alcoholic chronic pancreatitis (ACP) is a fibroinflammatory disease of the pancreas. However, metabolic basis of ACP is not clearly understood. In this study, we evaluated differential pancreatic injury in hepatic alcohol dehydrogenase deficient (ADH-) deer mice fed chronic ethanol (EtOH), chronic plus binge EtOH, and chronic plus binge EtOH and fatty acid ethyl esters (FAEEs, nonoxidative metabolites of EtOH) to understand the metabolic basis of ACP. Hepatic ADH- and ADH normal (ADH+) deer mice were fed Lieber-DeCarli liquid diet containing 3% (w/v) EtOH for three months. One week before the euthanization, chronic EtOH fed mice were further administered with an oral gavage of binge EtOH with/without FAEEs. Blood alcohol concentration (BAC), pancreatic injury and inflammatory markers were measured. Pancreatic morphology, ultrastructural changes, endoplasmic reticulum (ER)/oxidative stress were examined using H & E staining, electron microscopy, immunostaining, and/or Western blot, respectively. Overall, BAC was substantially increased in chronic EtOH fed groups of ADH- vs. ADH+ deer mice. A significant change in pancreatic acinar cell morphology, with mild to moderate fibrosis and ultrastructural changes evident by dilatations and disruption of ER cisternae, ER/oxidative stress along with increased levels of inflammatory markers were observed in the pancreas of chronic EtOH fed groups of ADH- vs. ADH+ deer mice. Furthermore, chronic plus binge EtOH and FAEEs exposure elevated BAC, enhanced ER/oxidative stress and exacerbated chronic EtOH-induced pancreatic injury in ADH- deer mice suggesting a role of increased body burden of EtOH and its metabolism under reduced hepatic ADH in initiation and progression of ACP.