Lipoxygenation of arachidonic acid by subcellular preparations from murine keratinocytes

Journal Article · Mon Oct 01 00:00:00 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), Vol. 83:4
• Country of Publication: United States
• Language: English

Related Subjects

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