Competitive incorporation of arachidonic acid analogs by cultured rat keratinocytes

• Published in: Journal of Nutritional Science and Vitaminology Vol. 47; no. 1; pp. 69 - 77
• Main Authors: Nakano, N. (Kinki Univ., Higashiosaka, Osaka (Japan). Faculty of Agriculture), Shirasaka, N, Kurihara, M, Takamatsu, M, Murakami, T, Yoshizumi, H, Tsuboi, R, Ogawa, H
• Format: Journal Article
• Language: English
• Published: Tokyo Center for Academic Publications Japan 2001
• Subjects: 5,8,11,14-cis-nonadecatetra-enoic acid; Animals; ARACHIDONIC ACID; Arachidonic Acid - metabolism; Arachidonic Acids - chemistry; Arachidonic Acids - metabolism; Binding, Competitive; Biological and medical sciences; CELL CULTURE; Cell Line; Chromatography, Gas; EPIDEMICS; Fatty Acids, Unsaturated - chemistry; Fatty Acids, Unsaturated - metabolism; Fundamental and applied biological sciences. Psychology; KERATIN; keratinocyte; Keratinocytes - metabolism; Phospholipids - biosynthesis; polyunsaturated fatty acid; POLYUNSATURATED FATTY ACIDS; RATS; Vertebrates: skin, associated glands, phaneres, light organs, various exocrine glands (salt gland, uropygial gland...), adipose tissue, connective tissue; Vertebrata; Mammalia; Rat; Analog; Animal; Rodentia; Polyunsaturated fatty acid; Lipids; Keratinocyte; Molecular competition; Skin; Arachidonic acid
• ISSN: 0301-4800; 1881-7742
• DOI: 10.3177/jnsv.47.69

Arachidonic acid (20:4 n-6) and its metabolic products, such as prosta-glandins and leukotrienes, have been known to be associated with skin inflammatory reac-tions. However, the mechanism of the competitive incorporation of 20:4 n-6 into ke-ratinocytes among polyunsaturated fatty acids (PUFAs) remains uncertain. To investigate the relationship between the molecular structure of PUFAs and the rate of incorporation of PUFAs into cells, a fetal rat skin keratinocyte (FRSK) cell line was used. The cells were incu-bated for 24 h with any two of the following arachidonic acid analogs: mead acid (20:3 n-9), dihomo-γ-linolenic acid (20:3 n-6), 11, 14, 17-cis-eicosatrienoic acid (20:3 n-3), arachi-donic acid (20:4 n-6), eicosapentaenoic acid (20:5 n-3) and 5, 8, 11, 14-cis-nonadecate-traenoic acid (19:4 n-5), at the ratio of 1:0, 0.5:0.5, or 0:1; and their incorporation into lipid was measured by capillary gas-liquid chromatography. The experiments indicated that 20:3 n-6 was preferentially incorporated into phospholipids of FRSK rather than 20:3 n-9 or 20:3 n-3, and 19:4 n-5 as well as 20:4 n-6 was preferentially incorporated into total cel-lular lipid and phospholipids rather than 20:3 n-9 or 20:5 n-3. When two PUFAs were added simultaneously to the medium, 19:4 n-5 most effectively reduced the competitive in-corporation of 20:4 n-6 into phospholipids. These results suggest that keratinocytes dis-criminate 20:4 n-6 from other arachidonic acid analogs by its double bond positions from the carboxyl group.