title: Changes in rat alveolar macrophageal antioxidant defense and reactive oxygen species release by high dietary vitamin E.
abstract: For the past decade there has been emphasis on the immunomodulatory effects of vitamin E apart from its established role as a free radical scavenger. In alveolar macrophages (AMs), the role of vitamin E supplementation has not yet been investigated sufficiently. In the present study we have evaluated the effects of high vitamin E (DL-alpha-tocopheryl acetate, alpha-TA) supplementation for 10 d on rat-alveolar macrophageal antioxidant defense and reactive oxygen species (ROS) release. There was an increase in plasma vitamin E content from 5.22 +/- 1.30, at 50 mg to 12.23 +/- 1.06 and 22.32 +/- 2.02 micrograms/mL at 250 and 1,250 mg alpha-TA/kg dietary supplementation. Alveolar macrophage-vitamin E content enhanced by 56 to 75% at 250 and 1,250 mg alpha-TA diet as compared with control diet. Superoxide dismutase activity decreased and catalase and glutathione peroxidase activities increased significantly in AMs of 250 and 1,250 mg alpha-TA diet-fed rats. Reduced glutathione, total glutathione, and glutathione-S-transferase activity in AMs did not change significantly at any of the high doses of alpha-TA supplementation. On stimulation of AMs by phorbol-12-myristate-13-acetate (PMA), there was 2.8- and 3.5-fold enhancement in superoxide (O2-.) and H2O2 production, respectively, at 50 mg alpha-TA dose. But this increase by PMA could not take place in AMs from animals supplemented with 250 and 1,250 mg alpha-TA. It may therefore be concluded that high alpha-TA supplementation in diet may equip the AMs with a stronger defense against oxygen-free radical mediated damage to them.
authors.affiliation: Department of Biophysics, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
authors.forename: V
authors.initials: V
authors.lastname: Pathania
authors.forename: N
authors.initials: N
authors.lastname: Syal
authors.forename: C M
authors.initials: CM
authors.lastname: Pathak
authors.forename: K L
authors.initials: KL
authors.lastname: Khanduja
mesh_terms: D000419:Albuminuria / Q000276:immunology / Q000378:metabolism; D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D002374:Catalase / Q000032:analysis; D019587:Dietary Supplements; D005979:Glutathione Peroxidase / Q000032:analysis; D005982:Glutathione Transferase / Q000032:analysis; D006861:Hydrogen Peroxide / Q000032:analysis; D016676:Macrophages, Alveolar / Q000276:immunology*; D008297:Male; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000276:immunology* / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D013482:Superoxide Dismutase / Q000032:analysis; D013481:Superoxides / Q000032:analysis; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014810:Vitamin E / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D017382:Reactive Oxygen Species; D013481:Superoxides; D014810:Vitamin E; D006861:Hydrogen Peroxide; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005982:Glutathione Transferase; D013755:Tetradecanoylphorbol Acetate