ISSN:
1432-2013
Keywords:
K+ channels
;
Acinar cells
;
Ensemble noise analysis
;
Current relaxation
;
Patch-clamp whole cell recording
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract The K+ channel in rat parotid gland acinar cells were investigated by ensemble current noise analysis in single isolated cells employing the giga-seal whole cell current recording mode. Sets of 20–40 identical de- and hyperpolarization voltage steps were applied and the resultant current records were processed by computer to obtain the mean and the variance of the current. The time-course of the mean current could be fitted by the sum of two exponentials, suggesting a 3-state model. The simplest plausible hypothesis is a model with one open and two closed states. Assuming this model, the relationship between the variance (σ2) and the mean current (I) could be fitted by the function σ2/I=i−I/N. The estimated single channeli/V-relations were similar to those taken from single channel current recordings, and the size of the population of channels per cell (N) was 76±26 (n=12). The validity of the model was tested by a successful simulation of the time-course of the variance.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00582956
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