The characteristics and oxidative modulation of large-conductance calcium-activated potassium channels in guinea-pig colon smooth muscle cells..
- Author:
Wei-Feng HUANG
1
;
Shou OUYANG
;
Hui ZHANG
Author Information
1. Xiamen Medical Research Institute, Xiamen, China.
- Publication Type:Journal Article
- MeSH:
Animals;
Colon;
cytology;
Guinea Pigs;
Hydrogen Peroxide;
pharmacology;
Large-Conductance Calcium-Activated Potassium Channels;
physiology;
Myocytes, Smooth Muscle;
physiology;
Oxidation-Reduction
- From:
Acta Physiologica Sinica
2009;61(3):285-291
- CountryChina
- Language:Chinese
-
Abstract:
To investigate the characteristics of large-conductance calcium-activated potassium channels (BK(Ca)) and the effect of hydrogen peroxide (H2O2) on BK(Ca) in guinea-pig proximal colon smooth muscle cells, single smooth muscle cells of guinea-pig colon were enzymatically isolated in low calcium solution containing papain (3 mg/mL), DTT (2 mg/mL), and bovine serum albumin (BSA, 2 mg/mL). Tissues were incubated at 36 degrees C in enzyme solution for 15 min and were then suspended in enzyme-free low calcium solution. Inside-out single channel recording technique was used to record BK(Ca) current. The intracellular (bath) and microelectrode solution both contained symmetrical high potassium. The BK(Ca) in guinea-pig colon smooth muscle cell possesses: 1) voltage-dependence, 2) high selectivity for potassium ion, 3) large conductance (223.7 pS+/-9.2 pS), 4) dependence of [Ca(2+)](i). Intracellular application of H2O2 decreased the open probability (P(o)) of BK(Ca) at low concentration (
