DIETARY SAFFLOWER OIL, COMPARED TO COCONUT OIL, DIFFERENTLY AFFECTS SPLENOCYTE FUNCTIONS IN OVALBUMIN-SENSITIZED RATS, LEADING TO ELEVATIONOF THE CIRCULATORY IGE

Prostaglandin E(2) (PGE(2)) and protein kinase C (PKC) affect prolifer ation of T cell and its subset which lead classical B cell isotype swi tching to immunoglobulin (Ig) E. In order to examine a mechanism(s) un derlying different levels of circulating IgE in response to dietary sa turated and polyunsaturated fats, production of PGE(2) and activity of PKC were measured in splenocytes of ovalbumin (OVA)-sensitized rats. Safflower oil (SO) diet-fed rats, compared to coconut oil diet-fed rat s, elevated serum levels of OVA-specific IgE and IgG2a and lowered the IgG1. Activity of PKC and concanavalin (Con) A-induced T-lymphoprolif eration were lowered in splenocytes from SO diet-fed rats. Production of PGE(2) was elevated splenocytes from SO diet-fed rats; however, thi s difference was disappeared when the cells were cultured with Con A. SO diet-fed rats increased proportion of linoleic acid but decreased t he arachidonic acid in splenocyte phospholipids. We conclude that diet ary polyunsaturated fatty acid is an important modulator of PGE(2) pro duction and PKC activity in splenic immune cells and it may play a rol e in the circulatory level of IgE.