AJP - Gastrointestinal and Liver Physiology, Vol 246, Issue 5 574-G579, Copyright © 1984 by American Physiological Society
Voltage clamping induces resistance and current-voltage plot changes in frog gastric mucosa
G. W. Kidder 3rd and M. G. Elrod
Changing the potential across the isolated frog gastric mucosa by voltage
clamping changes the measured resistance of the tissue in two ways. An
immediate change in resistance results from changing the measuring position
on the nonlinear current-voltage (I-V) plot. Subsequent to this, the
resistance changes slowly with a half-time of about 3 min, a change that is
not predicted by a previous model for voltage transients and that implies
slow changes in membrane resistance following changes in intracellular ion
content. The I-V plot over the range examined shows three breakpoints;
changing clamp voltage alters the position of two of these breakpoints as
well as the slope of the connecting resistances. The central breakpoint
agrees with the potential at zero current and varies with it as the clamp
potential is changed, as predicted from a diode model for breakpoint
generation.
