A chloride channel in mouse pancreatic acinar cells is activated by so-dium taurocholate and dependent on extracellular calcium but not reac-tive oxygen species pathway
AIM:To investigate the activation of Cl-channels by sodium taurocholate(NaTC)in mouse pan-creatic acinar cells.METHODS:The single isolated pancreatic acinar cells from FVB/N mice were prepared using colla-genase digestion method.Whole-cell patch clamp technique was performed to record the currents.Intracellular adenosine triphosphate(ATP)dependence of the channels was examined via eliminating ATP from the pipette solution.Anion per-meability of the channels was investigated with ion-exchange method.The pharmacological characteristics of the channels was confirmed by two Cl-channel blockers.The volume sensitivity of the channels was detected using 47%hypertonic bathing solution.Extracellular Ca2+dependence of activating the channels was examined through eliminating Ca2+from the bathing solution.Intracellular reactive oxygen species(ROS)level was detected by an oxidation-sensitive fluorescent probe,2',7'-dichlorofluorescin diacetate.The experiment was repeated 6 times in each group.RESULTS:Extracellular application of 5 mmol/L sodium taurocholate induced a Cl-current,exhibiting the properties of outward-rectification,a se-lectivity sequence of I->Br-≥Cl->gluconate-and intracellularATP dependence(P<0.01).The currents were inhibited by chloride channel blocker 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid disodium salt hydrate(DIDS)and tamoxifen and by 47%hypertonicity stimulation(P<0.01).When ROS production was scavenged by N-acetyl-L-cysteine,the sodi-um taurocholate-induced Cl-currents were unaffected.The effect of sodium taurocholate on ROS production did not alter with the treatment with DIDS.Sodium taurocholate failed to induce Cl-currents when Ca2+was absent in extracellular bath-ing solution(P>0.05).CONCLUSION:Sodium taurocholate activates Cl-channels in mouse pancreatic acinar cells,which is dependent on extracellular Ca2+but not ROS pathway.
sodium taurocholatepancreatic acinar cellschloride channelcalciumrreactive oxygen species
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