Objective: The purpose of this paper was to study the electrophysiological properties and the type of potassium channels on cell membrane in the stria vascularis pericytes in cochlear of guinea pig.
Methods: Firstly examined the expression of the stria vascularis pericytes by desmin, a marker of pericytes, in cochlear of guinea pig with immunofluorescent method. Using whole-cell patch clamp recording techniques to observe electrophysiological properties in the cochlear pericytes in stria vascularis of guinea pig.
Results: Pericytes were predominately distributed in the capillaries of cochlea.The average membrane capacitance, resistance, and potential of a single pericyte in stria vascularis were(5.9±0.3)pF, (2.2±0.3)GΩ and (-30.9±1.2)mV, respectively by using patch clamp technique. In addition, the average current density of cochlear pericyte was voltage-sensitive (Vh from 0 to + 60 mV, in 20 mV steps). The pericytes exhibited outward current and this property could be blocked by TEA (tetraethylammonium) 1 mmol/L, a large-conductance calcium-activated potassium channel(BKCa)inhibitor and 4-AP (4-aminopyridine) 1 mmol/L, a voltage-dependent K(+) channels(KV) channel blocker. TEA blocked the outward current from (296.2±35.9)pA to (163.7±16.8)pA and 4-AP blocked the outward current from (248.7±39.8)pA to (158.0±38.0)pA.
Conclusion: These results suggest that pericytes in stria vascularis have BKCa and KV channels.