[Effect of hypoxia on membrane potential and input resistance of cultured carotid body glomus cells in rat].

Carotid bodies were removed from rats (50-100 g) under sodium pentobarbitone anesthesia and dissociated by mechanical means to obtain small clusters and single glomus cells to be cultured under normoxic (5% CO2, 20% O2, 75% N2, 37 degrees C) or hypoxic (5% CO2, 10% O2, 85% N2, 37 degrees C) conditions for 3-5 days. They are respectively called normoxic or hypoxic cells. The membrane potential (MP) and input resistance (Ri) of the normoxic cells were measured under normoxic condition as controls. The results show that MP of the normoxic cells measured under hypoxic condition increased in about half the cells and decreased in an other half. The percentage of cells with increased MP was higher under 100% N2 than under hypoxia. The MP and Ri of the hypoxic cells measured under normoxia were not significantly different from the control values, but the MP and Ri of the hypoxic cells measured under hypoxia were significantly higher than those of the control (MP: P < 0.01, Ri: P < 0.05). The results suggest that oxygen sensing of the carotid body is reflected by changes in MP and Ri of the glomus cells.