Ethanol impairs calcium homeostasis following CCK-8 stimulation in mouse pancreatic acinar cells.
Alcohol consumption has long been associated with cell damage, and it is thought that it is involved in approximately 40% of cases of acute pancreatitis. In the present study, we have investigated the early effects of acute ethanol exposure on cholecystokinin octapeptide (CCK-8)-evoked calcium (Ca2+) signals in mouse pancreatic acinar cells. Cells were loaded with fura-2 and the changes in fluorescence were monitorized using a spectrofluorimeter. Our results show that stimulation of cells with 1 nM CCK-8 led to a transient increase in [Ca2+]c, which consisted of an initial increase followed by a decrease of [Ca2+]c toward a value close to the prestimulation level. In the presence of 50mM ethanol, CCK-8 lead to a greater Ca2+ mobilization compared to that obtained with CCK-8 alone. The peak of CCK-8-evoked Ca2+ response, the "steady-state level" reached 5 min after stimulation, the rate of decay of [Ca2+]c toward basal values and the total Ca2+ mobilization were significantly affected by ethanol pretreatment. Thapsigargin (Tps) induced an increase in [Ca2+]c due to its release from intracellular stores. After stimulation of cells with CCK-8 or Tps in the presence of 50mM ethanol, a greater [Ca2+]c peak response, a slower rate of decay of [Ca2+]c, and higher values of [Ca2+]c were observed. The effects of ethanol might result from a delayed or reduced Ca2+ extrusion from the cytosol toward the extracellular space by plasma membrane Ca2+ adenosine triphosphatase (ATPase), or into the cytosolic stores by the sarcoendoplasmic reticulum Ca2+-ATPase. Participation of mitochondria in Ca2+ handling is also demonstrated. The actions of ethanol on CCK-8 stimulation of cells create a situation potentially leading to Ca2+ overload, which is a common pathological precursor that mediates pancreatitis.
González
Antonio
A
Department of Physiology, Cell Physiology Research Group, Faculty of Veterinary Sciences, University of Extremadura, Avenida Universidad s/n, PO Box 643, Cáceres, Spain. agmateos@unex.es
Pariente
José A
JA
Salido
Ginés M
GM
D000818:Animals; D002118:Calcium / Q000502:physiology*; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D000431:Ethanol / Q000494:pharmacology*; D006706:Homeostasis / Q000187:drug effects* / Q000502:physiology; D008297:Male; D051379:Mice; D046790:Pancreas, Exocrine / Q000187:drug effects* / Q000502:physiology; D012844:Sincalide / Q000494:pharmacology*
D000431:Ethanol; D012844:Sincalide; D002118:Calcium