Mitogen-induced oscillations of membrane potential and Ca2+ in human fibroblasts.
Using the whole-cell technique, we have measured recurring hyperpolarizations induced by fetal calf serum and bradykinin in human fibroblasts. By coupling fura-2 microfluorimetry to electrophysiology, we have also measured directly cytosolic Ca2+ and found that Ca2+ oscillations occur in synchrony with membrane currents. Mitogen stimulation of cells in which intracellular K+ had been replaced with Cs+ resulted in the abolishment of the outward current. We conclude then that the mitogen-induced recurring hyperpolarizations in human fibroblasts are due to the opening of Ca2(+)-activated K+ channels.
Peres
A
A
Dip di Fisiologia e Biochimica Gen. dell' Universita di Milano, Italy.
Giovannardi
S
S
D001572:Benzofurans; D001920:Bradykinin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002462:Cell Membrane / Q000502:physiology; D002478:Cells, Cultured; D005347:Fibroblasts / Q000187:drug effects / Q000502:physiology*; D005456:Fluorescent Dyes; D016257:Fura-2; D008564:Membrane Potentials / Q000187:drug effects; D008856:Microscopy, Fluorescence; D008934:Mitogens / Q000494:pharmacology*; D015221:Potassium Channels / Q000502:physiology
D001572:Benzofurans; D005456:Fluorescent Dyes; D008934:Mitogens; D015221:Potassium Channels; D001920:Bradykinin; D002118:Calcium; D016257:Fura-2