scholarly journals Studies on lipid peroxidation in normal and tumour tissues. The Yoshida rat liver tumour

1988 ◽  
Vol 250 (1) ◽  
pp. 247-252 ◽  
Author(s):  
K H Cheeseman ◽  
S Emery ◽  
S P Maddix ◽  
T F Slater ◽  
G W Burton ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Rat Liver ◽  
Alpha Tocopherol ◽  
Novikoff Hepatoma ◽  
Nadph Cytochrome ◽  
Transport Chain ◽  
Initiation And Propagation ◽  
Normal Rat ◽  
Cytochrome P 450 ◽  
Nadph Cytochrome C Reductase

Reduced rates of lipid peroxidation have been observed in Yoshida hepatoma cells and microsomes when compared with appropriate control tissue (normal rat liver) under the same pro-oxidant conditions. The pro-oxidant conditions used were incubation with NADPH+ADP+iron or ascorbate+iron or exposure to gamma-irradiation. As previously shown with the Novikoff hepatoma, the relative concentrations of alpha-tocopherol and polyunsaturated fatty acids are important in conferring resistance to lipid peroxidation in the Yoshida hepatoma. Furthermore, NADPH-cytochrome c reductase and the NADPH-cytochrome P-450 electron transport chain, which are involved in the initiation and propagation of certain types of lipid peroxidation, are found at very much reduced levels in the Yoshida hepatoma. The relative importance of these aberrations are discussed.

scholarly journals Studies on lipid peroxidation in normal and tumour tissues. The Novikoff rat liver tumour

1986 ◽  
Vol 235 (2) ◽  
pp. 507-514 ◽  
Author(s):  
K H Cheeseman ◽  
M Collins ◽  
K Proudfoot ◽  
T F Slater ◽  
G W Burton ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Fatty Acids ◽  
Rat Liver ◽  
Fatty Acid Content ◽  
Normal Liver ◽  
Rat Hepatocytes ◽  
Tumour Cells ◽  
Alpha Tocopherol ◽  
Polyunsaturated Fatty Acid Content ◽  
Normal Rat

A study has been made of the factors that contribute to the decreased rates of lipid peroxidation under different pro-oxidant conditions in intact Novikoff tumour cells, and in microsomal suspensions prepared from Novikoff tumour cells, compared with isolated normal rat hepatocytes and microsomal suspensions prepared from normal rat liver. The pro-oxidant conditions were the addition of either NADPH, NADPH + ADP + iron, NADPH + CCl4 or ascorbate+iron to the experimental systems used, or exposure to gamma-radiation. Contributory factors to the lower rates of lipid peroxidation observed include: a significant decrease in the polyunsaturated fatty acid content of Novikoff cells or Novikoff microsomes; the decreases are especially marked for the C20:4 and C22:6 fatty acids; a very marked reduction in NADPH-cytochrome c reductase; and no detectable content of cytochrome P-450. Another, and in our opinion critical, contribution to the diminished rate of lipid peroxidation in the tumour material is the substantial increase in alpha-tocopherol relative both to total lipid and to methylene-interrupted double bonds in fatty acids. Moreover, the alpha-tocopherol is the major contributor to lipid-soluble chain-breaking antioxidant in lipid extracts of normal liver and of Novikoff tumour material.

Sign in / Sign up

Export Citation Format

Share Document