Angiotensin evokes in polyploid rat glioma cells hyperpolarization-depolarization responses and cross-desensitization with bradykinin

Angiotensins I, II and III induced a hyperpolarizing response of up to 1 min duration followed by a depolarizing response of up to 4 min when applied by pressure pulses or iontophoresis to polyploid rat glioma cells C6-4-2. The hyperpolarization (depolarization) was associated with a 50% decrease (no measurable change) in membrane resistance. The reversal potential (ca. −90 mV) of the hyperpolarization most likely points to an increased K + conductance. Cells desensitized to angiotensins on application of high doses of either angiotensins or bradykinin.