The effect of dietary lipids on the thermotropic behaviour of rat liver and heart mitochondrial membrane lipids

1983 ◽  
Vol 734 (1) ◽  
pp. 114-124 ◽  
Author(s):  
Edward J. McMurchie ◽  
Mahinda Y. Abeywardena ◽  
John S. Charnock ◽  
Robert A. Gibson
1980 ◽  
Vol 58 (10) ◽  
pp. 1147-1155 ◽  
Author(s):  
E. A. Hosein ◽  
Hung Lee ◽  
Ilan Hofmann

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.


2011 ◽  
Vol 107 (5) ◽  
pp. 647-659 ◽  
Author(s):  
Manar Aoun ◽  
Christine Feillet-Coudray ◽  
Gilles Fouret ◽  
Béatrice Chabi ◽  
David Crouzier ◽  
...  

Dietary lipids are known to affect the composition of the biological membrane and functions that are involved in cell death and survival. The mitochondrial respiratory chain enzymes are membrane protein complexes whose function depends on the composition and fluidity of the mitochondrial membrane lipid. The present study aimed at investigating the impact of different nutritional patterns of dietary lipids on liver mitochondrial functions. A total of forty-eight Wistar male rats were divided into six groups and fed for 12 weeks with a basal diet, lard diet or fish oil diet, containing either 50 or 300 g lipid/kg. The 30 % lipid intake increased liver NEFA, TAG and cholesterol levels, increased mitochondrial NEFA and TAG, and decreased phospholipid (PL) levels. SFA, PUFA and unsaturation index (UI) increased, whereas MUFA andtrans-fatty acids (FA) decreased in the mitochondrial membrane PL in 30 % fat diet-fed rats compared with 5 % lipid diet-fed rats. PL UI increased with fish oil dietv.basal and lard-rich diets, and PLtrans-FA increased with lard dietv.basal and fish oil diets. The 30 % lipid diet intake increased mitochondrial membrane potential, membrane fluidity, mitochondrial respiration and complex V activity, and decreased complex III and IV activities. With regard to lipid quality effects, β-oxidation decreased with the intake of basal or fish oil diets compared with that of the lard diet. The intake of a fish oil diet decreased complex III and IV activities compared with both the basal and lard diets. In conclusion, the characteristics and mitochondrial functions of the rat liver mitochondrial membrane are more profoundly altered by the quantity of dietary lipid than by its quality, which may have profound impacts on the pathogenesis and development of non-alcoholic fatty liver disease.


2014 ◽  
Vol 15 (8) ◽  
pp. 797-810 ◽  
Author(s):  
Joao Monteiro ◽  
Catarina Morais ◽  
Paulo Oliveira ◽  
Amalia Jurado

1980 ◽  
Vol 188 (2) ◽  
pp. 329-335 ◽  
Author(s):  
M E Koller ◽  
I Romslo

Rat liver mitochondria accumulate protoporphyrin IX from the suspending medium into the inner membrane in parallel with the magnitude of the transmembrane K+ gradient (K+in/K+out). Only protoporphyrin IX taken up in parallel with the transmembrane K+ gradient is available for haem synthesis. Coproporphyrins (isomers I and III) are not taken up by the mitochondria. The results support the suggestion by Elder & Evans [(1978) Biochem. J. 172, 345-347] that the prophyrin to be taken up by the inner mitochondrial membrane belongs to the protoporphyrin(ogen) IX series. Protoporphyrin IX at concentrations above 15 nmol/mg of protein has detrimental effects on the structural and functional integrity of the mitochondria. The relevance of these effects to the hepatic lesion in erythropoietic protoporphyria is discussed.


Author(s):  
Roger F. Castilho ◽  
André R. Meinicke ◽  
Anibal E. Vercesi ◽  
Marcelo Hermes-Lima

2007 ◽  
Vol 282 (37) ◽  
pp. 26908-26916 ◽  
Author(s):  
Audrey Faye ◽  
Catherine Esnous ◽  
Nigel T. Price ◽  
Marie Anne Onfray ◽  
Jean Girard ◽  
...  

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