González Antonio, Granados María P, Salido Ginés M, Pariente José A
Faculty of Veterinary Sciences, Department of Physiology, University of Extremadura, Avenida Universidad s/n E-10071, Cáceres, Spain.
Cell Signal. 2003 Nov;15(11):1039-48. doi: 10.1016/s0898-6568(03)00067-6.
In the present study, we have employed confocal laser scanning microscopy to investigate the effect that stimulation of mouse pancreatic acinar cells with the secretagogue cholecystokinin (CCK) has on mitochondrial activity. We have monitored changes in cytosolic as well as mitochondrial Ca2+ concentrations, mitochondrial membrane potential and FAD autofluorescence by loading the cells with fluo-3, rhod-2 or JC-1, respectively. Our results show that stimulation of cells with cholecystokinin led to release of Ca2+ from intracellular stores that then accumulated into mitochondria. In the presence of the hormone a depolarization of mitochondrial membrane potential was observed, which partially recovered; in addition a transient increase in FAD autofluorescence could be observed. Similarly, treatment of cells with thapsigargin induced increases in mitochondrial Ca2+ and FAD autofluorescence, and depolarized mitochondria. Pretreament of cells with thapsigargin blocked cholecystokinin-evoked changes. Similar results were obtained when the cells were incubated in the presence of rotenone, which blocks the mitochondrial electron transport chain. Our findings are consistent with changes in mitochondrial activity in response to stimulation of pancreatic acinar cells with cholecystokinin. Following stimulation, mitochondria take up Ca2+ that could in turn activate the mitochondrial machinery that may match the energy supply necessary for the cell function during secretion, suggesting that Ca2+ can act as a regulator of mitochondrial activity.
在本研究中，我们采用共聚焦激光扫描显微镜来研究用促分泌素胆囊收缩素（CCK）刺激小鼠胰腺腺泡细胞对线粒体活性的影响。我们分别用fluo-3、rhod-2或JC-1加载细胞，监测了胞质以及线粒体Ca2+浓度、线粒体膜电位和FAD自发荧光的变化。我们的结果表明，用胆囊收缩素刺激细胞会导致Ca2+从细胞内储存库释放，然后积累到线粒体中。在激素存在的情况下，观察到线粒体膜电位去极化，随后部分恢复；此外，还可观察到FAD自发荧光短暂增加。同样，用毒胡萝卜素处理细胞会导致线粒体Ca2+和FAD自发荧光增加，以及线粒体去极化。用毒胡萝卜素预处理细胞可阻断胆囊收缩素引起的变化。当细胞在鱼藤酮存在的情况下孵育时也获得了类似结果，鱼藤酮可阻断线粒体电子传递链。我们的发现与胆囊收缩素刺激胰腺腺泡细胞后线粒体活性的变化一致。刺激后，线粒体摄取Ca2+，这反过来可能激活线粒体机制，以匹配分泌过程中细胞功能所需的能量供应，这表明Ca2+可作为线粒体活性的调节剂。
