Potassium and calcium currents and action potentials in mouse Balb/c 3T3 fibroblasts.
The electrical properties of Balb/c 3T3 mouse fibroblasts were studied with the whole-cell patch clamp technique. In current clamp mode a resting potential of -75.5 +/- 2.1 mV was recorded. In voltage clamp mode an inward current was also observed at potentials negative to Vm. This current crossed the 0-current axis at a voltage near Vm, and rectified at more positive potentials; the degree of rectification was dependent on [K+]o. At potentials positive to -30 mV a transient inward current was observed, showing a peak amplitude of -193 +/- 36 pA at +10 mV; the current amplitude was dependent on voltage and [Ca2+]o, it was strongly increased by 20 mM BaCl2 and abolished by 2 microM verapamil and 1 microM nifedipine. These cells, in response to depolarizing stimuli, develop slow action potentials, probably supported by the Ca2+ current.
Lovisolo
D
D
Dipartimento di Biologia Animale, Universitá di Torino, Italy.
Alloatti
G
G
Bonelli
G
G
Tessitore
L
L
Baccino
F M
FM
D000200:Action Potentials; D000818:Animals; D002118:Calcium / Q000502:physiology*; D015220:Calcium Channels / Q000502:physiology; D002478:Cells, Cultured; D004553:Electric Conductivity; D005347:Fibroblasts / Q000502:physiology; D051379:Mice; D008807:Mice, Inbred BALB C; D011188:Potassium / Q000502:physiology*
D015220:Calcium Channels; D011188:Potassium; D002118:Calcium