Relationship of dietary vitamin E to prostanoid production in rat lung

To study the relationship between dietary vitamin E and pulmonary prostaglandin (PG) production, weanling rats were fed either a vitamin E-deficient (-Vit E) or a supplemented diet (+Vit E) containing 200 mg all-rac-α-tocopheryl acetate/kg diet. Four rats from each group were killed after 9, 12, and 15 wk. Serum tocopherol in the deficient animals was 0.28 ± 0.17 μg/ml, compared to 13.81 ± 0.61 μg/ml in the supplemented group. Peroxidation in lung tissue, as measured by malondialdehyde levels, was significantly higher (p<0.001) in -Vit E than in +Vit E (0.210 ± 0.043 and 0.037 ±0.010 μmoles/g tissue, respectively). Excized, minced lung was incubated in Krebs-Ringer bicarbonate buffer at 37°C with shaking in an atmosphere of 95% O₂, 5% CO₂ for 10 min. Production of PGE, PGF_2α, thromboxane B₂ (TXB₂), and the prostacyclin metabolite, 6-keto-PGF_1α, in lung tissue was measured by radioimmunoassay. No significant differences in prostanoid levels were found between the -Vit E and +Vit E groups.