[Study on the electrophsiological properties in the stria vascularis pericytes in cochlear of guinea pig].
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.


CONCLUSIONS
These results suggest that pericytes in stria vascularis have BKCa and KV channels.
Department of Physiology, the Key Laboratory of Xinjiang Endemic and Ethnic Diseases, Medical College of Shihezi University; Shihezi 832002, China.
Y H
YH
Liu
Department of Physiology, the Key Laboratory of Xinjiang Endemic and Ethnic Diseases, Medical College of Shihezi University; Shihezi 832002, China.
Y P
YP
Wang
Department of Physiology, the Key Laboratory of Xinjiang Endemic and Ethnic Diseases, Medical College of Shihezi University; Shihezi 832002, China.
Y
Y
Wang
Department of Physiology, the Key Laboratory of Xinjiang Endemic and Ethnic Diseases, Medical College of Shihezi University; Shihezi 832002, China.
K T
KT
Ma
Department of Physiology, the Key Laboratory of Xinjiang Endemic and Ethnic Diseases, Medical College of Shihezi University; Shihezi 832002, China.
J Q
JQ
Si
Department of Physiology, the Key Laboratory of Xinjiang Endemic and Ethnic Diseases, Medical College of Shihezi University; Shihezi 832002, China.
L
L
Li
D015761:4-Aminopyridine / Q000494:pharmacology; D000818:Animals; D003051:Cochlea / Q000502:physiology*; D055724:Electrophysiological Phenomena / Q000187:drug effects; D006168:Guinea Pigs; D018408:Patch-Clamp Techniques; D020286:Pericytes / Q000737:chemistry / Q000187:drug effects / Q000502:physiology*; D026902:Potassium Channel Blockers / Q000494:pharmacology; D015221:Potassium Channels / Q000032:analysis*; D024681:Potassium Channels, Calcium-Activated / Q000032:analysis; D013316:Stria Vascularis / Q000737:chemistry / Q000166:cytology*; D019789:Tetraethylammonium / Q000494:pharmacology
D026902:Potassium Channel Blockers; D015221:Potassium Channels; D024681:Potassium Channels, Calcium-Activated; D019789:Tetraethylammonium; D015761:4-Aminopyridine