Evidence for a P O2‐sensitive K+ channel in the type‐I cell of the rabbit carotid body

FEBS Letters

Delpiano, M.A.¹  Hescheler, J.² 

[1] Max-Planck-Institut für Systemphysiologie, Rheinlanddamm 201, 4600 Dortmund 1 FRG;II Physiologisches Institut, Universität des Saarlandes, 6650 Homburg/Saar, FRG

关键词: Hypoxia;    Patch-clamp;    Oxygen partial pressure;    Single-channel current;    (Carotid body;    Type-I cell);   

DOI  :  10.1016/0014-5793(89)80623-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Type-I cells of rabbit carotid bodies were studied with the patch-clamp technique in the whole-cell and on the cell-attached configuration. Cells exhibiting resting potentials of about −40 mV under normoxic conditions (P _O2: 20 kPa), depolarized during hypoxia (P _O2: 3.7 kPa). Hypoxia did not affect inward Ca²⁺ currents but inactivated outward K⁺ currents in voltage-clamp experiments. Single-channel currents recorded for the cell-attached mode showed a slope conductance of about 137 pS and a 0 mV reversal potential under symmetrical K⁺ concentration (140 mM). The open-probability (P _o) of the single channel was dependent on the extracellular P _O2. These data demonstrate the existence of a P _O2-sensitive K⁺ channel in type-I cells, which may account for cell depolarization and the resulting chemosensory response.

【 授权许可】

Unknown