title: Phospholipid peroxidation in tumor promoter-exposed mouse skin.
abstract: We have investigated lipid peroxidation in the skin of CD1 mice following single or repeated topical applications of the tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA). A substantial accumulation of hydroxyphospholipids, to levels 3-5 times control values, followed exposure to two or more TPA treatments (24-72 h intervals), whereas single applications were ineffective. Sodium borohydride reduction increased the yield of product by approximately 50%, suggesting the additional presence of phospholipid hydroperoxides in the oxidized lipids. Straight phase HPLC analysis of the constituent hydroxy fatty acids, followed by gas chromatography/mass spectrometry, revealed that oxidized derivatives of linoleic acid, including 9- and 13-hydroxyoctadecadienoic acids (9- and 13-HODE), were the primary products. Stereochemical analysis showed ratios of S to R stereoisomers of 1.3 for 13-HODE and 1.27 for 9-HODE, which implied that TPA-induced peroxidation was primarily due to free radical oxidation, although a partial contribution of enzyme (lipoxygenase) activity is possible. The TPA-induced peroxidation was greater in the epidermis than in the dermis. Pre-exposure of mouse skin to the anti-inflammatory agent fluocinolone acetonide, antioxidants and enzyme (phospholipase A2 and lipoxygenase) inhibitors lowered the peroxidation response to subsequent exposure to TPA. Phospholipid peroxidation products may be useful markers of oxygen radical production in TPA-exposed mouse skin with possible relevance to tumor promotion.
authors.affiliation: Department of Pediatric Gastroenterology/Nutrition, Vanderbilt University Medical Center, Nashville, TN 37232.
authors.forename: J K
authors.initials: JK
authors.lastname: Beckman
authors.forename: F
authors.initials: F
authors.lastname: Bagheri
authors.forename: C
authors.initials: C
authors.lastname: Ji
authors.forename: I A
authors.initials: IA
authors.lastname: Blair
authors.forename: L J
authors.initials: LJ
authors.lastname: Marnett
mesh_terms: D062365:Aminobenzoates / Q000494:pharmacology; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D001894:Borohydrides / Q000494:pharmacology; D000001:Calcimycin / Q000494:pharmacology; D002723:Chlorobenzoates; D002851:Chromatography, High Pressure Liquid; D002934:Cinnamates / Q000494:pharmacology; D004817:Epidermis / Q000187:drug effects* / Q000378:metabolism; D005260:Female; D005446:Fluocinolone Acetonide / Q000494:pharmacology; D005609:Free Radicals; D008401:Gas Chromatography-Mass Spectrometry; D006868:Hydrolysis; D008041:Linoleic Acids / Q000032:analysis; D044243:Linoleic Acids, Conjugated; D015227:Lipid Peroxidation; D016859:Lipoxygenase Inhibitors; D009637:Masoprocol / Q000494:pharmacology; D051379:Mice; D018632:Mice, Inbred SENCAR; D010741:Phospholipases A / Q000037:antagonists & inhibitors; D054467:Phospholipases A2; D010743:Phospholipids / Q000378:metabolism*; D011281:Pregnatrienes / Q000494:pharmacology; D013237:Stereoisomerism; D013755:Tetradecanoylphorbol Acetate / Q000633:toxicity*; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis; D062367:ortho-Aminobenzoates
chemical_list: D062365:Aminobenzoates; D000975:Antioxidants; D001894:Borohydrides; D002723:Chlorobenzoates; D002934:Cinnamates; D005609:Free Radicals; D008041:Linoleic Acids; D044243:Linoleic Acids, Conjugated; D016859:Lipoxygenase Inhibitors; D010743:Phospholipids; D011281:Pregnatrienes; D017392:Thiobarbituric Acid Reactive Substances; D062367:ortho-Aminobenzoates; D005446:Fluocinolone Acetonide; C074965:U 74389F; C024347:9-hydroxy-10,12-octadecadienoic acid; D000001:Calcimycin; C024348:13-hydroxy-9,11-octadecadienoic acid; D009637:Masoprocol; C025364:sodium borohydride; C060048:2-(4-amylcinnamoyl)amino-4-chlorobenzoic acid; D010741:Phospholipases A; D054467:Phospholipases A2; C053356:U 74500A; D013755:Tetradecanoylphorbol Acetate