MODULATION OF DEGRANULATION AND SUPEROXIDE GENERATION IN HUMAN NEUTROPHILS BY UNSATURATED FATTY-ACIDS OF ODD CARBON NUMBERS

Unsaturated fatty acids of odd carbons, 13:1(12), 17:1(10trans), 19:1( 7) and 19:1(10) inhibited release of myeloperoxidase (MPG) from fMet-L eu-Phe-cytochalasin B-treated neutrophils. The inhibitory effect was s maller than that of aseanostatins which have been isolated as microbia l-derived free fatty acids with a methyl blanch (i-14:0 and ai-15:0) ( Journal of Antibiotics (1991) 44, 524-532). These unsaturated fatty ac ids also inhibited lactoferrin release by the same treatment. On the o ther hand, 13:1(12), 15:1(10) and 19:1(10) inhibited fMet-Leu-Phe-stim ulated superoxide generation of neutrophils, and the fatty acids 15:1( 10), 17:(10) and 19:2(10,13) induced superoxide generation in both uns timulated cells and the cell-free system. However, none of unsaturated fatty acids of odd carbons tested inhibited P-glucuronidase release, whereas 15:1(10), 17:1(10), 19:1(7), 19:1(10) and 19:2(10,13) rather e nhanced an increase in P-glucuronidase activity liberated from cells a t high concentrations over 35 mu M, indicating cellular damages by the se fatty acids. These observations suggest that unsaturated free fatty acids having odd carbons such as 13, 15, 17 and 19 may act as modulat ors of neutrophil functions including degranulation and superoxide gen eration.