Effect of chronic alcohol feeding and withdrawal on rat liver plasma membrane structure and function: a study of binding of [3H]prazosin to the membrane bound α1-adrenergic receptor

1983 ◽  
Vol 32 (7) ◽  
pp. 1321-1323 ◽  
Author(s):  
Hung Lee ◽  
Esau A. Hosein ◽  
Benjamin Rovinski
Keyword(s):  
Plasma Membrane ◽  
Rat Liver ◽  
Adrenergic Receptor ◽  
Membrane Structure ◽  
Structure And Function ◽  
Chronic Alcohol ◽  
Liver Plasma Membrane ◽  
Membrane Structure And Function ◽  
Membrane Bound ◽  
And Function

The influence of chronic ethanol feeding to rats on liver mitochondrial membrane structure and function

1980 ◽  
Vol 58 (10) ◽  
pp. 1147-1155 ◽  
Author(s):  
E. A. Hosein ◽  
Hung Lee ◽  
Ilan Hofmann
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Rat Liver ◽  
Mitochondrial Membrane ◽  
Membrane Structure ◽  
Membrane Lipids ◽  
Specific Activity ◽  
Structure And Function ◽  
Membrane Structure And Function ◽  
And Function

Arrhenius plots were generated on the activity of rat liver mitochondrial cytochrome c oxidase from Metrecal–sucrose fed controls and Metrecal–alcohol fed experimentals. Chronic alcohol feeding resulted in diminished specific activity of cytochrome c oxidase and abolition of the discontinuity temperature at 17.5 °C found in the controls. Twenty-four hours after alcohol withdrawal, a discontinuity temperature reappeared at 14.4 °C; at 48 h it increased to 22.6 °C and returned to normal (17.4 °C) at 72 h. Such liver mitochondria also showed a decreased capacity to oxidize the acetyl group of acetyl carnitine immediately following prolonged alcohol feeding. When the assay was performed following withdrawal from alcohol 24 h later, oxidation was enhanced and this effect persisted for another 48 h. These latter results revealed a diminished capacity of such mitochondria to oxidize short chain fatty acids during alcohol feeding and the reverse during alcohol withdrawal.These results, complemented by thermographic data obtained through differential scanning calorimetry (DSC) reinforced the view that chronic alcoholic feeding induced adaptive changes in the fluidity of rat liver mitochondrial membrane lipids. Moreover, they demonstrated that in the microenvironment of the membrane-bound enzymes on withdrawal from ethanol, the membrane readapts to the new conditions without alcohol. This involved modulation of membrane structure and function and at the same time demonstrated a role for the membrane in the expression of tolerance and functional dependence on alcohol.

Chronic alcohol feeding and its withdrawal on the structure and function of the rat liver plasma membrane: a study with 125I-labelled glucagon binding as a metabolic probe

1982 ◽  
Vol 60 (9) ◽  
pp. 1171-1176 ◽  
Author(s):  
Hung Lee ◽  
E. A. Hosein
Keyword(s):  
Plasma Membrane ◽  
Rat Liver ◽  
Plasma Membranes ◽  
Structure And Function ◽  
Scatchard Analysis ◽  
Chronic Alcohol ◽  
Alcohol Administration ◽  
Liver Plasma Membranes ◽  
And Function ◽  
Chronic Alcohol Administration

The effect of chronic alcohol administration on the structure and function of the rat liver plasma membranes has been investigated. Chronic alcohol administration did not affect the yield of these membranes using conventional isolation procedures. The extent of plasma membrane enrichment or contamination with other interior membranes was identical in the control and alcoholic preparations. The binding of 125I-labelled glucagon to these experimental liver plasma membranes was significantly decreased. Scatchard analysis of the high affinity sites showed a significant reduction [Formula: see text] in receptor number rather than binding affinity, which was not altered. This anomaly persisted through 72-h withdrawal of alcohol. These data suggest that very stable changes were induced in these liver plasma membranes after prolonged alcohol ingestion.

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