Effects of ubiquinones on spontaneous membrane hyperpolarizations in a cloned monkey kidney cell line

The effects of ubiquinones on spontaneous membrane hyperpolarizations in JTC-12 cells were examined. There were three types of spontaneous hyperpolarizations; rhythmic, sporadic and oscillatory types. The oscillatory type was not observed in the standard medium, whereas it was observed in sodium-free medium or in the medium containing 300 nM coenzyme Q10. The number of the cells showing spontaneous hyperpolarizations significantly increased in the medium containing coenzyme Q10 (47.7%) as compared to the control (18.9%). However, coenzyme Q1 (500 nM) showed no effects.