Distribution of membrane potential of aortic media cells and fibroblasts in culture.

The distribution of membrane potential (Em) of aortic media cells and fibroblastoid kidney cells (both derived from calf and monkey) was investigated by using dense cell layers. Fibroblastoid kidney cells showed a symmetric distribution of Em with a mean of -10.6 +/- 0.29 mV for calf and -12.1 +/- 0.31 mV for monkey (m +/- sm). In aortic media cell lines, however, a wide bimodal distribution of Em was found (between -4 mV and -32 mV). The peaks were at about -17 mV and -27 mV in calf aortic media cells, and at about -13 mV and -22 mV in monkey aortic media cells. The bimodality of Em distribution of cultured aortic media cells may be typical for this cell type. Presumably, this pattern reflects two cell populations in different states of differentiation or maturation.