Effects of the hepatocarcinogenic peroxisome-proliferating hypolipidemic agents Clofibrate and Nafenopin on the rat liver cell membrane enzymes γ-glutamyltranspeptidase and alkaline phosphatase and on the early stages of liver carcinogenesis

Although the livers of rats treated with agents known to suppress bilirubin transport appeared relatively normal on routine histological sections, cytochemical and electron microscopic preparations revealed marked changes in: (a) levels of alkaline phosphatase and apparent ATPase activities of the cell membrane at the sinusoids, bile canaliculi, and between adjacent cells; (b) morphology of the bile canaliculi such as dilatation, fragmentation, vesiculation and reduced numbers of microvilli; (c) the number of lysosomes and their distribution within the cell. Similar changes in the cytochemistry of the liver cell were induced by extrahepatic obstruction.

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Protective Effect ofN-Acetylcysteine on Rat Liver Cell Membrane During Methanol Intoxication

Journal of Pharmacy and Pharmacology ◽

10.1211/0022357001774183 ◽

2000 ◽

Vol 52 (5) ◽

pp. 547-552 ◽

Cited By ~ 12

Author(s):

I. DOBRZYÑSKA ◽

E. SKRZYDLEWSKA ◽

I. KASACKA ◽

Z. FIGASZEWSKI

Keyword(s):

Cell Membrane ◽

Protective Effect ◽

Rat Liver ◽

Liver Cell ◽

Methanol Intoxication ◽

Liver Cell Membrane

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Separation and Partial Characterization Of Rat Liver Cell Membrane Components

Preparative Biochemistry ◽

10.1080/00327487108081940 ◽

1971 ◽

Vol 1 (1) ◽

pp. 205-220

Author(s):

Mildred K. Fleetwood ◽

Roy F. Davis ◽

Seymour Bakerman

Keyword(s):

Cell Membrane ◽

Rat Liver ◽

Liver Cell ◽

Partial Characterization ◽

Liver Cell Membrane ◽

Membrane Components

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Hyperpolarization of hepatocytes by 2,5-AM: implications for hepatic control of food intake

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1997.272.3.r874 ◽

1997 ◽

Vol 272 (3) ◽

pp. R874-R878

Author(s):

E. Scharrer ◽

R. Rossi ◽

D. A. Sutter ◽

M. C. Seebacher ◽

S. Boutellier ◽

...

Keyword(s):

Membrane Potential ◽

Cell Membrane ◽

Rat Liver ◽

Liver Cell ◽

Liver Slice ◽

Flufenamic Acid ◽

K Channel ◽

Channel Blockers ◽

K Channels ◽

Liver Cell Membrane

Because 2,5-anhydro-D-mannitol (2,5-AM) seems to stimulate feeding by acting on the liver and because the hepatic membrane potential has been suggested to play an important role in control of feeding ("potentiostatic" hypothesis), we investigated the effect of 2,5-AM on the membrane potential of liver cells with microelectrodes using a superfused liver slice technique. 2,5-AM (2.5 mM), which reduces intracellular ATP in rat liver, hyperpolarized the liver cell membrane in mouse and rat liver slices by 4-7 mV. This hyperpolarization was reversed by quinine (1 mM), an unspecific blocker of Ca2+-dependent K+ channels, and abolished by apamin (20 nM), a blocker of Ca2+-activated K+ channels with low conductance. Amiloride at 10(-3) M, but not at 10(-6) M, or a low-Na medium (26 mM) also eliminated the hyperpolarization. The K+ channel blockers cetiedil (50 microM), glibenclamide (30 microM), and Ba2+ (5 mM); flufenamic acid (100 microM), a blocker of nonselective cation channels; and ouabain (1 mM), an inhibitor of the Na+-K+-adenosinetriphosphatase, did not significantly influence the 2,5-AM-induced hyperpolarization. It is concluded that 2,5-AM hyperpolarizes the liver cell membrane by activating Ca2+-dependent K+ channels. This activation seems to be impaired when the Na+/H+ exchanger is inhibited by amiloride or a low-Na+ medium. The findings also imply that the hyperphagic effect of 2,5-AM observed in rats is not associated with a decrease in the hepatic membrane potential, as postulated by the potentiostatic hypothesis.

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