12(R)-hydroxyicosatetraenoic acid: a cytochrome P450-dependent arachidonate metabolite that inhibits Na/sup +/, K/sup +/-ATPase in the cornea

Journal Article · Sun Nov 01 04:00:00 EST 1987 · Proc. Natl. Acad. Sci. U.S.A.; (United States)

DOI:https://doi.org/10.1073/pnas.84.22.8125· OSTI ID:6618704

Schwartzman, M L; Balazy, M; Masferrer, J; Abraham, N G; McGiff, J C; Murphy, R C

When corneal microsomes were incubated with arachidonic acid in the presence of an NADPH-generating system, four polar metabolites (compounds A-D) were formed. Synthesis of these metabolites could be inhibited by carbon monoxide, SKF 525A, and anti-cytochrome c reductase antibodies. One of the metabolites, compound C, was found to inhibit partially purified Na/sup +/, K/sup +/-ATPase from the corneal epithelium in a dose-dependent manner. After compound C was purified by TLC and HPLC, it was found to have a UV absorption spectrum with a maximum absorbance at 236 nm suggesting the presence of a conjugated diene. Mass spectrometric analysis using positive- and negative-ionization modes was carried out on derivatized compound C. Abundant fragment ions were consistent with compound C being a monooxygenated derivative of arachidonic acid with a hydroxyl substituent at carbon-12 of the icosanoid backbone; all deuterium atoms from (/sup 2/H/sub 8/)arachidonate were retained in the structure. Compound C was characterized as a 12-hydroxyicosatetraenoic acid. However, only 12(R) isomer was found to be an inhibitor of the Na/sup +/, K/sup +/-ATPase from the corneal epithelium, suggesting that the biologically active compound C was 12(R)-hydroxyy-5,8,10,14-icosatetraenoic acid. Such an inhibitor of Na/sup +/, K/sup +/-ATPase synthesized in the cornea may have an important role in regulating ocular transparency and aqueous human secretion.

• Research Organization: Univ. of Colorado Health Sciences Center, Denver (USA)
• OSTI ID: 6618704
• Journal Information: Proc. Natl. Acad. Sci. U.S.A.; (United States), Journal Name: Proc. Natl. Acad. Sci. U.S.A.; (United States) Vol. 84:22; ISSN PNASA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ABSORPTION SPECTRA
ACID ANHYDRASES
ARACHIDONIC ACID
ATP-ASE
BIOCHEMISTRY
BODY
BODY AREAS
CARBON 14 COMPOUNDS
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
CHEMISTRY
CHROMATOGRAPHY
CORNEA
CYTOCHROMES
DERIVATIZATION
DEUTERIUM COMPOUNDS
ENZYME INHIBITORS
ENZYMES
EYES
FACE
HEAD
HYDROGEN COMPOUNDS
HYDROLASES
INHIBITION
LABELLED COMPOUNDS
LIQUID COLUMN CHROMATOGRAPHY
MASS SPECTROSCOPY
METABOLITES
MONOCARBOXYLIC ACIDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
PHOSPHOHYDROLASES
PIGMENTS
PROTEINS
SENSE ORGANS
SEPARATION PROCESSES
SPECTRA
SPECTROSCOPY
THIN-LAYER CHROMATOGRAPHY
TRITIUM COMPOUNDS