Related Experiment Video
Updated: Sep 27, 2026
In vitro Measurements of Tracheal Constriction Using Mice
Published on: June 25, 2012
[Changes of K+ channel behaviors in airway smooth muscle from asthmatic guinea-pigs]
1Department of Respiratory Medicine, First Affiliated Hospital, First Military Medical University, Guangzhou.
Objective:
To observe asthma-induced changes of single K+ channel behaviors in acutely dissociated airway smooth muscle of guinea-pig.
Methods:
The resting membrane potential (MP) was measured in whole-cell recording configuration. The elementary currents flowing through single K+ channel were recorded in cell-attached patches.
Results:
The properties in asthmatic group were as follows: (1) MP was decreased from -70.3 +/- 3.5 mV to -62.8 +/- 5.6 mV. (2) In the same depolarization conditions, the amplitudes of currents decayed and conductant values were decreased with significantly difference (about 51%) from the values obtained from the control group. (3) Open time constants of fast- and slow-open states shortened markedly to 25% and 7% of controls respectively. Shut time constants were prolonged. (4) Open probability showed voltage-dependence and was decreased in the same voltage range.
Conclusions:
Asthmic airway hyperreactivity-related kinetic properties of K+ channel deficits, which may result a reduced threshold of excitation.
