Effect of chronic ethanol consumption on the content of alpha-tocopherol in subcellular fractions of rat liver.
The effects of long-term administration of ethanol (35% of total energy for 6-8 weeks) on the distribution and concentration of alpha-tocopherol in subcellular fractions of rat liver have been studied. Marker enzymes were measured in all fractions. The highest concentration of alpha-tocopherol was found in the light mitochondrial fraction both in ethanol-fed and control rats, 754 +/- 104 and 1127 +/- 126 pmol/mg protein, respectively. The microsomal, heavy mitochondrial, and nuclear fractions also had high concentrations of alpha-tocopherol, whereas the cytosolic fraction contained minor amounts. In the light mitochondrial fraction we found the highest concentration of alpha-tocopherol in lysosomes, whereas small amounts were detected in peroxisomes. In the microsomal fraction the highest concentration was found in the Golgi apparatus. The content of alpha-tocopherol in the light mitochondrial fraction was reduced by 33% (p less than 0.02) in the ethanol-fed group as compared to the controls. In the other fractions no significant differences between the two groups were observed. Long term administration of ethanol promoted, however, a further enrichment of alpha-tocopherol (178% higher than controls) in the Golgi apparatus, possibly due to reduced secretion of very low density lipoprotein-associated alpha-tocopherol.
Hagen
B F
BF
National Institute of Forensic Toxicology, University of Oslo, Norway.
Bjørneboe
A
A
Bjørneboe
G E
GE
Drevon
C A
CA
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D004032:Diet; D000431:Ethanol / Q000494:pharmacology*; D008099:Liver / Q000201:enzymology / Q000378:metabolism* / Q000648:ultrastructure; D008297:Male; D010743:Phospholipids / Q000378:metabolism; D011506:Proteins / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013347:Subcellular Fractions / Q000187:drug effects / Q000378:metabolism*; D014810:Vitamin E / Q000378:metabolism*
D010743:Phospholipids; D011506:Proteins; D014810:Vitamin E; D000431:Ethanol