Relationships between vitamin E status and erythrocyte stability in sheep.
Stability of erythrocytes from sheep with vitamin E deficiency (E-deficient) was compared by two haemolytic tests, one based on osmotic fragility in hypotonic saline and the other on detergent sensitivity in Tween 20. Relationships between haemolysis, plasma alpha-tocopherol concentration and creatine kinase (CK) activity were evaluated. E-deficient animals were clinically healthy but had elevated (greater than 1000 iu per 1) CK activities and low (less than 1 mumol per 1) alpha-tocopherol concentrations compared with control sheep (less than 500 iu per 1 and greater than 1.5 mumol per 1, respectively). Erythrocytes from E-deficient sheep were markedly more susceptible to detergent treatment than those from controls, but osmotic fragility was similar in both groups. Detergent sensitivity was directly related to plasma alpha-tocopherol concentration and CK activity but not to erythrocyte glutathione peroxidase activity. Within 24 h of supplementation (300 mg alpha-tocopherol subcutaneously) of E-deficient sheep, plasma alpha-tocopherol concentrations were increased, CK activities decreased and erythrocyte susceptibility to detergent-induced haemolysis was significantly reduced. Concentrations of alpha-tocopherol returned rapidly (less than 3 days) to pre-supplement values, although decreased haemolytic responses persisted longer (greater than 7 days). Cells from E-deficient animals were protected against detergent-induced haemolysis by preincubation with alpha-tocopherol in vitro. The results indicate that detergent sensitivity of erythrocytes may provide the basis of a simple functional test for vitamin E deficiency in sheep.
Moredun Research Institute, Edinburgh, U.K.
L M
LM
Stevenson
D G
DG
Jones
D000818:Animals; D003402:Creatine Kinase / Q000097:blood; D004912:Erythrocytes / Q000187:drug effects / Q000502:physiology*; D005260:Female; D005979:Glutathione Peroxidase / Q000097:blood; D006454:Hemoglobins / Q000032:analysis; D006461:Hemolysis; D008297:Male; D009996:Osmotic Fragility; D011136:Polysorbates / Q000494:pharmacology; D012756:Sheep; D012757:Sheep Diseases / Q000097:blood*; D014810:Vitamin E / Q000008:administration & dosage / Q000097:blood* / Q000494:pharmacology; D014811:Vitamin E Deficiency / Q000097:blood / Q000662:veterinary*
D006454:Hemoglobins; D011136:Polysorbates; D014810:Vitamin E; D005979:Glutathione Peroxidase; D003402:Creatine Kinase