Lipoxygenation of arachidonic acid by subcellular preparations from murine keratinocytes

Journal Article · Mon Oct 01 04:00:00 EDT 1984 · J. Invest. Dermatol.; (United States)

DOI:https://doi.org/10.1111/1523-1747.ep12340250· OSTI ID:6001488

Ziboh, V A; Casebolt, T L; Marcelo, C L; Voorhees, J J

In these studies, we examined the possibility that cell-free preparations from murine keratinocytes possess 5-lipoxygenase activity in addition to the well-established cyclooxygenase pathway of arachidonic acid (AA) in these cells. Our data demonstrated that the high-speed (105,000 g) supernatant preparations of the murine keratinocytes metabolized (14C)AA into labeled lipoxygenase products. Portions of these radioactive metabolites cochromatographed and comigrated with 12-HETE (a marker for 12-lipoxygenase pathway) and with authentic LTB4 (a marker for 5-lipoxygenase pathway) on silicic acid column chromatography and by thin-layer chromatography (TLC) in two solvent systems respectively. Identity of the novel 14C which comigrated with LTB4 on both TLC and column chromatography was verified further by cochromatography of the free acid with authentic LTB4 on a reverse phase (RP) and the methyl esters on a straight phase high-pressure liquid chromatography. Incubation of the cell-free preparations with (14C)AA in the presence of ETYA, NDGA (inhibitors of cyclooxygenase and lipoxygenase pathways) as well as with 15-HETE (an inhibitor of lipoxygenase pathway) resulted in decreased formation of (14C) 12-HETE and the (14C)LTB4-like metabolite. On the contrary, incubations of the cell-free extracts with (14C) AA in the presence of indomethacin (a cyclooxygenase inhibitor) resulted in increased biosynthesis of the labeled lipoxygenase metabolites. These data indicate the existence of enzymes in soluble fraction of murine keratinocyte which can catalyze the transformation of (14C) AA into products of both the 12- and 5-lipoxygenase pathways.

• Research Organization: Univ. of California School of Medicine, Davis
• OSTI ID: 6001488
• Journal Information: J. Invest. Dermatol.; (United States), Journal Name: J. Invest. Dermatol.; (United States) Vol. 83:4; ISSN JIDEA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMAL CELLS
ANTIOXIDANTS
ARACHIDONIC ACID
BIOLOGICAL PATHWAYS
CARBON 14 COMPOUNDS
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
CHROMATOGRAPHY
ENZYME ACTIVITY
ENZYME INHIBITORS
ENZYMES
ISOTOPE APPLICATIONS
KERATIN
LABELLED COMPOUNDS
METABOLISM
METABOLITES
MONOCARBOXYLIC ACIDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
OXIDATION
OXIDOREDUCTASES
OXYGENASES
PROTEINS
SCLEROPROTEINS
SEPARATION PROCESSES
TRACER TECHNIQUES