Electrophysiological properties of isolated rat liver cells

Abstract

The electrophysiological properties of isolated rat liver cells were studied using the patch clamp method in whole-cell configuration. The membrane potential in isolated hepatocytes was -42 +/- 7 mV (n = 20). The input resistance (Rin) and the time constant (tau m) were 51 +/- 17 M (the range of 34 to 180 M omega) (n = 20) and 4.2 +/- 1.0 msec (the range of 3 to 16.5 ms) (n = 20). Assuming that the specific membrane capacitance is 1 microF/cm2, the membrane resistance and membrane capacitance were 42. +/- 9.0 K omega cm2 and 87 +/- 27 pF. These values indicate that isolated rat hepatocytes are not abnormally permeable or leaky. The current-voltage relationship was linear with no rectification. The depolarizing pulse from the resting potential did not induce fast or slow inward currents even when norepinephrine or high Ca2 (3.6 mM) were applied. This indicates that there is no voltage-sensitive Ca2+ channel in the isolated hepatocytes.

KATP Channels Regulate Mitogenically Induced Proliferation in Primary Rat Hepatocytes and Human Liver Cell Lines

“…Moreover, the addition of K ϩ channel openers to the external solution shifted the reversal potential toward the equilibrium potential for K ϩ . Previously recorded hepatic K ϩ currents have been either linear or Ca 2ϩ -dependent inward rectifiers (18,19). Our electrophysiological data are in agreement with additional demonstrations of K ϩ channel mRNA expression in liver cells.…”

A Calcium Flux Is Required for Circadian Rhythm Generation in Mammalian Pacemaker Neurons

“…Indeed, hepatocytes contain Ca 2ϩ channels that are mainly receptor activated but may also include voltageactivated Ca 2ϩ channels (Sawanobori et al, 1989;Brereton et al, 1997).…”

Calcium: its modulation in liver by cross-talk between the actions of glucagon and calcium-mobilizing agonists

“…A further complication to studies of Ca2+ inflow is that there is mounting evidence that more than one system facilitates Ca2+ entry in the plasma membrane of liver cells (Barritt et al, 1981;Hughes et al, 1986;Altin and Bygrave, 1987a;Barritt and Hughes, 1991;Llopis et al, 1992). The potentially useful technique of patch-clamping appears to be technically difficult in liver plasma membranes (see, e.g., Sawanobori et al, 1989;Barritt and Hughes, 1991).…”