Membrane potential measurements during rat liver regeneration

Wondergem, Robert; Harder, David R.

doi:10.1002/jcp.1041020210

Cited by 34 publications

(11 citation statements)

References 15 publications

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“…Perfusion was shifted to K+-free medium after the electrode was withdrawn from the lumen, revealing no potential deflection. Electrode artifacts accounting for the small luminal potential change therefore appear unlikely perfused liver from -29 to -34 mV (Claret et al, 1970;Wondergem & Harder, 1980;Cohen et al, 1982). A second criterion for impalement quality is the value of the membrane resistance which was 3 kf~ cm 2 in the present study (1/gs- Table 1).…”

Section: Discussionmentioning

confidence: 95%

Cell membrane and transepithelial voltages and resistances in isolated rat hepatocyte couplets

et al. 1987

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The basic electrical properties of an isolated rat hepatocyte couplet (IRHC) system have been analyzed using classical techniques of epithelial electrophysiology, including measurement of electric potentials, resistances and intracellular ion activities. Applications of these techniques are discussed with respect to their limitations in small isolated cells. Mean intracellular and intracanalicular membrane potentials ranged from -23.7 to -46.7 and -4.3 to -5.9 mV, respectively. Membrane resistances were determined using an equivalent circuit analysis modified according to the geometry of the IRHC system. Resistances of the sinusoidal (basolateral) and canalicular (luminal) cell membranes and tight junctions averaged 0.15 and 0.78 G omega and 25 m omega, respectively. The cells are electrically coupled via low resistance intercellular communications (approximately 58 M omega). Intracellular ion activities for Na+, K+ and Cl- averaged 12.2, 88.1 and 17.7 mmol/liter, respectively. The basolateral membrane potential reveals a permeability sequence of PK greater than PCl greater than PNa. The luminal potential showed minimal dependence on changes in transjunctional ion gradients, indicating a poor ion selectivity of the paracellular pathway. The electrogenic (Na+-K+)-ATPase contributes little to the luminal and cellular negative electric potential. Therefore, the luminal potential probably results from the secretion of impermeant ions and a Donnan distribution of permeant ions, a mechanism which provides the osmotic driving force for bile formation. By providing the unique opportunity to measure luminal potentials, this isolated hepatocyte system permits study of secretory mechanisms for the first time in a mammalian gland using electrophysiologic techniques.

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Section: Discussionmentioning

confidence: 95%

Cell membrane and transepithelial voltages and resistances in isolated rat hepatocyte couplets

et al. 1987

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“…Although K + is essentially permeant between intra and extracellular phases such as nerve or muscle, Cl − is the permeant ion in other lower voltage tissues. The resting membrane potentials in liver cells (hepatocytes) was shown by direct measurement with intracellular electrodes to be in the range between −50 and −20 mV . The resting membrane potential is widely thought to be a “diffusion potential” resulting from the higher intracellular K + concentration relative to the extracellular concentration.…”

Section: δG′ Of Cytoplasmic Atp Hydrolysismentioning

confidence: 99%

The “great” controlling nucleotide coenzymes

et al. 2019

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Nucleotide coenzymes dot the map of metabolic pathways providing energy to drive the reactions of the pathway and play an important role in regulating and controlling energy metabolism through their shared potential energy, which is widely unobserved due to the paradox that the energy in the coenzyme pools cannot be determined from the concentration of the coenzyme couples. The potential energy of the nucleotide couples in the mitochondria or the cytoplasm is expressed in the enzyme reactions in which they take part. The energy in these couples, [NAD+]/[NADH], [NADP+]/[NADPH], [acetyl CoA]/[CoA], and [ATP]/[ADP]x[Pi], regulates energy metabolism. The energy contained in the couples can be altered by suppling energy equivalents in the form of ketones, such as, D‐β‐hydroxybutyrate to overcome insulin resistance, to restore antioxidants capacity, to form potential treatments for Alzheimer's and Parkinson's diseases, to enhance life span, and to increase physiological performance. © 2019 IUBMB Life, 71(5):565–579, 2019

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“…Moreover, the expression of the receptor on the plasma membrane depends on many different factors that can regulate cell traffic and membrane anchoring. Some of those factors are altered during liver regeneration (Leoni et al, 1987;Wondergren and Harder, 1980;MacManus and Whitfield, 1981). Thus, the LDL receptor protein on total cell membranes and on plasma membranes was measured by immunoblotting, using a polyclonal anti-rat liver apoB, E receptor antibody.…”

Section: Level Of Ldl Receptor Mrna In the Livermentioning

confidence: 99%

Early induction of LDL receptor gene during rat liver regeneration

Bocchetta

Bruscalupi

Castellano

et al. 1993

Journal Cellular Physiology

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After partial hepatectomy in the rat, there is substantial lipid accumulation in the liver. No information is available on the possible role of receptor-mediated endocytosis in this process. Since the low density lipoprotein (LDL) receptor is stimulated as a part of an early growth response in cell culture (Ellsworth et al.: Biochem. J. 279:175-187, 1991), the metabolism of this receptor during liver regeneration was studied. The mRNA and membrane protein level of the receptor were measured in the liver and in the adrenal glands at different times after partial hepatectomy, corresponding to different phases of the cell cycle. A discontinuous pattern of receptor expression is detectable in the regenerating liver; a large increase of mRNA and membrane protein occurs at an early time (2-4 h), suggesting that there is induction of LDL receptor gene transcription shortly after partial hepatectomy. This response seems specific for the liver following injury since the adrenal receptor does not show a different pattern in partially hepatectomized rats and sham-operated controls. After returning to control levels, the LDL receptor again increases slightly above control at 24 h, a time when cell replication begins.

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Membrane potential measurements during rat liver regeneration

Cited by 34 publications

References 15 publications

Cell membrane and transepithelial voltages and resistances in isolated rat hepatocyte couplets

Cell membrane and transepithelial voltages and resistances in isolated rat hepatocyte couplets

The “great” controlling nucleotide coenzymes

Early induction of LDL receptor gene during rat liver regeneration

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