Modulation of Inwardly Rectifying K⁢ Channel by Intracellular and Extracellular pH in Bovine Aortic Endothelial Cells

• 영문명: Modulation of Inwardly Rectifying K^⁢ Channel by Intracellular and Extracellular pH in Bovine Aortic Endothelial Cells
• 발행기관: 대한생리학회-대한약리학회
• 저자명: Kyu-Sang Park In Deok Kong Joong Woo Lee Hyewhon Rhim Young Chul Kim Insuk So Ki Whan Kim
• 간행물 정보: 『The Korean Journal of Physiology & Pharmacology』제6권 제5호, 255~260쪽, 전체 6쪽
• 주제분류: 의약학 > 의학일반
• 파일형태: PDF
• 발행일자: 2002.01.01

영문 초록

The effects of intracellular and extracellular pH on the inwardly rectifying K^⁢ (IRK) channel of the bovine aortic endothelial cells (BAECs) were examined using whole-cell patch-clamp technique. The IRK current, efficiently blocked by Ba^2⁢ (200μM), is the most prominent membrane current in BAECs, which mainly determines the resting membrane potential. The expression of Kir2.1 was observed in BAECs using reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. Intracellular alkalinization, elicited by the extracellular substitution of NaCl with NH₄Cl (30 mM), significantly augmented the amplitude of IRK current. On the contrary, the amplitude of IRK current was attenuated by the Na-acetate (30 mM)-induced intracellular acidification. The changes in extracellular pH also closely modulated the amplitude of IRK current, which was decreased to 40.2⁑1.3% of control upon switching the extracellular pH to 4.0 from 7.4. The extracellular pH value for half-maximal inhibition (pK) of IRK current was 5.11. These results demonstrate that the activity of IRK channel in BAECs, probably Kir2.1, was suppressed by proton at both sides of plasma membrane.

키워드

Inwardly rectifying K^⁢ channel Intracellular pH Extracellular pH