Ethanol exerts dual effects on calcium homeostasis in CCK-8-stimulated mouse pancreatic acinar cells

BACKGROUND: A significant percentage of patients with pancreatitis often presents a history of excessive alcohol consumption. Nevertheless, the patho-physiological effect of ethanol on pancreatitis remains poorly understood. In the present study, we have investigated the early effects of acute ethanol exposure on CCK-8-evoked Ca(2+ )signals in mouse pancreatic acinar cells. Changes in [Ca(2+)](i )and ROS production were analyzed employing fluorescence techniques after loading cells with fura-2 or CM-H(2)DCFDA, respectively. RESULTS: Ethanol, in the concentration range from 1 to 50 mM, evoked an oscillatory pattern in [Ca(2+)](i). In addition, ethanol evoked reactive oxygen species generation (ROS) production. Stimulation of cells with 1 nM or 20 pM CCK-8, respectively led to a transient change and oscillations in [Ca(2+)](i). In the presence of ethanol a transformation of 20 pM CCK-8-evoked physiological oscillations into a single transient increase in [Ca(2+)](i )in the majority of cells was observed. Whereas, in response to 1 nM CCK-8, the total Ca(2+ )mobilization was significantly increased by ethanol pre-treatment. Preincubation of cells with 1 mM 4-MP, an inhibitor of alcohol dehydrogenase, or 10 μM of the antioxidant cinnamtannin B-1, reverted the effect of ethanol on total Ca(2+ )mobilization evoked by 1 nM CCK-8. Cinnamtannin B-1 blocked ethanol-evoked ROS production. CONCLUSION: ethanol may lead, either directly or through ROS generation, to an over stimulation of pancreatic acinar cells in response to CCK-8, resulting in a higher Ca(2+ )mobilization compared to normal conditions. The actions of ethanol on CCK-8-stimulation of cells create a situation potentially leading to Ca(2+ )overload, which is a common pathological precursor that mediates pancreatitis.