Determination of the amounts of free arachidonic acid in resident and activated rabbit alveolar macrophages by fluorometric high performance liquid chromatography

Abstract

An improved method of high performance liquid chromatography (HPLC) has been developed for the separation and quantitation of low levels of free fatty acids as they occur in mammalian tissues. The fatty acid analysis is based on the esterification of the carboxylic group with 9-anthryldiazomethane (ADAM). HPLC separation and fluorescence measurement of fatty acid ADAM esters allow the determination of pmole amounts of fatty acids. The amounts of free fatty acids of resident and activated alveolar macrophages were determined by the fluorometric HPLC method. There were approximately 2 micrograms/10(6) cells of free fatty acids. In resident macrophages, free 20:4 was a minor component (0.8% of total free fatty acids), while significant amounts of 20:4 were found in the total glycerophospholipids, representing 16.6% of the total fatty acids. A marked increase in amounts of 20:4 (8 times) occurred in activated macrophages stimulated for 1 hr with opsonized zymosan. Small but significant increases (1.5 times) also occurred in other fatty acids. These results show that the release reaction of fatty acids was not selective for 20:4 in alveolar macrophages after the challenge with opsonized zymosan.

Effects of Corn Oil Addition to the Diet on the Energy Metabolism of Heart, Liver and Kidney of Female Rats

“…In the same probes (tissues and mitochondria) non-esterified fatty acids (NEFA) were determined by HPLC equipped with a fluorescence detector, following the derivatization with 9-aminophenanthrene according to the methods described by Ikeda et al (1984) and Nakagawa & Waku (1985). Routinely C 14:O (myristic acid), C 16:O (palmitic acid), C 18:O (stearic acid), C 18:l (oleic acid), C 18 : 2 (linoleic acid) and C 20 : 4 (arachidonic acid) could be separated and determined quantitatively.…”

Cyclooxygenase‐catalyzed formation of 9‐hydroxylinoleic acid by guinea pig alveolar macrophages under non‐stimulated conditions

“…In recent years emphasis has been placed on the production and the biological significance of arachidonic acid-derived mediators, including prostaglandins and leukotrienes. Macrophage membrane phospholipids, however, also contain linoleic acid which can be liberated by phospholipase activity upon cell stimulation [4]. Little information is available on the production of linoleic acid-derived mediators from inflammatory cells, and their possible role in the inflammatory…”

Biochemical Mechanisms of Oxfenicine Cardiotoxicity

“…following derivation with 9-aminophenanthrene according to the methods described by Ikeda et al [1984] and Nakagawa and Waku [1985]. Routinely C 14:0 (myrislic acid), C 16:0 (palmitic acid), C 18:0 (stearic acid), C 18:1 (oleic acid), C 18:2 (linolcic acid) and C 20:4 (arachidonic acid) could be sepa rated and determined quantitatively.…”