Alpha-tocopherol binding activity of red blood cells in smokers

M Bellizzi, A K DuttaRoy, G G Duthie, W P T James

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Abstract

Despite high plasma levels of vitamin E, red blood cell membranes contain relatively low levels of vitamin E. This suggests the existence of a selective vitamin E uptake/regeneration system in human red blood cell membranes. alpha-Tocopherol binding sites on human red blood cells are thought to be involved in the uptake of alpha-tocopherol from the plasma. To understand the role of the uptake system we have compared the alpha-tocopherol content and binding activity of red blood cells from smokers and non-smokers. The specific binding of [H-3]alpha-tocopherol to pure red blood cell preparations from smokers (n = 7, 28.4 +/- 2.8 years) was 30.6 +/- 3.2 fmoles per 3 x 10(8) red blood cells and for non-smokers (n = 17, 27.9 +/- 1.3 years) was 41.7 +/- 3.7 fmoles per 3 x 10(8) red blood cells. Thus alpha-tocopherol uptake activity was significantly lower in smokers (P = 0.05). Red blood cells from smokers contained less (1.8 +/- 0.4 mu g/gHb) alpha-tocopherol than non-smokers (2.8 +/- 0.3 mu g/gHb), (P < 0.05), despite plasma levels of alpha-tocopherol being similar: 12.9 +/- 0.8 mu M in non-smokers vs. 12.7 +/- 0.5 mu M in smokers. However, adjusting plasma alpha-tocopherol for total plasma cholesterol plus triacylglycerols showed alpha-tocopherol levels were higher (P < 0.01) in non-smokers (2.84 +/- 0.10 mu mol alpha-tocopherol/mmol [cholesterol+triacylglycerol]) than in smokers (2.36 +/- 0.11 mu mol alpha-tocopherol/mmol [cholesterol+triacylglycerol]). The reduced alpha-tocopherol levels in red blood cells from smokers may be due to impairment of alpha-tocopherol uptake activity. The reduced levels of alpha-tocopherol in smokers red blood cells was not associated with any changes in cell membrane fluidity. At present it is not known whether supplementation of smokers with vitamin E would normalise the alpha-tocopherol uptake activity of red blood cells.

Original languageEnglish
Pages (from-to)105-112
Number of pages8
JournalFREE RADICAL RESEARCH
Volume27
Issue number1
Publication statusPublished - 1997

Keywords

  • smoking
  • alpha-tocopherol uptake
  • red blood cells
  • alpha-tocopherol
  • membrane fluidity
  • vitamin-E
  • erythrocyte-membranes
  • lipid-peroxidation
  • antioxidant status
  • cigarette-smoking
  • plasma
  • metabolism
  • nonsmokers
  • platelets
  • proteins

Cite this

Bellizzi, M., DuttaRoy, A. K., Duthie, G. G., & James, W. P. T. (1997). Alpha-tocopherol binding activity of red blood cells in smokers. FREE RADICAL RESEARCH, 27(1), 105-112.