Arachidonic Acid Metabolism in Cultured Mouse Keratinocytes

• Published in: Journal of investigative dermatology Vol. 85; no. 1; pp. 64 - 69
• Main Authors: Kondoh, Hiroaki, Sato, Yoshio, Kanoh, Hideo
• Format: Journal Article
• Language: English
• Published: Danvers, MA Elsevier Inc 01-07-1985; Nature Publishing
• Subjects: Animals; Animals, Newborn; Arachidonic Acid; Arachidonic Acids - metabolism; Biological and medical sciences; Blood; Calcimycin - pharmacology; Cells, Cultured; Culture Media; Dinoprostone; Fundamental and applied biological sciences. Psychology; Mice; Phospholipases - physiology; Phospholipids - metabolism; Prostaglandins E - metabolism; Skin - cytology; Stimulation, Chemical; Tetradecanoylphorbol Acetate - pharmacology; Tritium; Vertebrates: skin, associated glands, phaneres, light organs, various exocrine glands (salt gland, uropygial gland...), adipose tissue, connective tissue; Cell culture; Phospholipase; Vertebrata; Mammalia; Mouse; Rodentia; Keratinocyte; Skin; Arachidonic acid; Metabolism
• ISSN: 0022-202X; 1523-1747
• DOI: 10.1111/1523-1747.ep12275349

We attempted to characterize the general features of arachidonate metabolism in cultured mouse keratinocytes. The cells labeled with [3H]arachidonate were stimulated by 12-O-tetradecanoylphorbol-13-acetate (TPA), inophore A23187, and fetal bovine serum (FBS). Common to the three substances, phosphatidylinositol, phosphatidylethanolamine, and phosphatidylcholine almost equally served as sources of arachidonate liberated by the action of phospholipase A2. The stimulation of phospholipase A2 action was observed in the order of A23187 > FBS > TPA. When stimulated by TPA or A23187, the radioactivity released into the extracellular medium was mostly found in prostaglandin (PG) E2. Formation of other PGs and hydroxyeicosatetraenoate (HETE) was extremely limited. In the case of stimulation by FBS, however, the released radioactivity was mainly associated with non-converted arachidonate. FBS also inhibited the TPA- and A23187-induced conversion of arachidonate to PGE2. Phospholipid degradation induced by the three stimulators was similarly dependent on extracellular Ca2+. The stimulation by FBS and A23187 was suppressed by calmodulin antagonists, though the effect of A23187 was much more sensitive to the antagonists when compared to that of FBS. We observed more than additive effects of the three stimulators when tested together.