PRODUCTION OF EICOSANOIDS DERIVED FROM 20 4N-6 AND 20/5N-3 IN PRIMARYCULTURES OF TURBOT (SCOPHTHALMUS-MAXIMUS) BRAIN ASTROCYTES IN RESPONSE TO PLATELET-ACTIVATING-FACTOR, SUBSTANCE-P AND INTERLEUKIN-1-BETA/

Primary cultures of turbot (Scophthalmus maximus) brain astroglial cel ls established in medium containing fetal bovine serum contain increas ed proportions of 18:1(n-9), total (n-9) and (n-6) polyunsaturated fat ty acids (PUFA) and greatly reduced (n-3) PUFA in comparison with turb ot brain. Supplementation with a mixture of 5 mu M eicosapentaenoic [2 0:5(n-3)] and 25 mu M docosahexaenoic [22:6(n-3)] acids for 4 days sig nificantly inreased the percentages of these acids in total cellular l ipid of turbot astrocytes and restored the (n-3) PUFA composition of t he cells to that found in turbot brain. Th production of prostaglandin s (PG) E and F of the 2- and 3-series and leukotrienes (LT) C-4 and C- 5 in response to various agonists was determined in PUFA-supplemented astrocytes. Calcium ionophore A23187, platelet activating factor and s ubstance P stimulated the production of both PGF and PGE. Interleukin- 1 beta significantly stimulated the production of PGF only. There were differences between the agonists in their effects on the relative lev els of 2- and 3-series PGs produced. Only very low amounts of LTC were produced by the turbot astrocytes, with only substance P showing a mi nor stimulatory effect.