THE FATTY-ACID COMPOSITION OF MATERNAL DIET AFFECTS LUNG PROSTAGLANDIN E-2 LEVELS AND SURVIVAL FROM GROUP-B STREPTOCOCCAL SEPSIS IN NEONATAL RAT PUPS

Dietary fatty acid effects upon the immune system may be mediated in p art by effects upon the synthesis of proinflammatory mediators. The ef fects of maternal dietary fatty acid composition upon lung prostagland in (PG) E-2 levels and survival from group B streptococcal (GBS) infec tion were investigated in neonatal rat pups. Beginning on d 2 of gesta tion and throughout lactation, pregnant dams were fed a purified diet whose fat source (22% of energy) was either corn oil or menhaden fish oil. On postnatal d 3, pups were randomly cross-fostered to dams of th e same diet group to minimize litter effects; litters were then culled to 10 pups per dam. On postnatal d 7, pups were either injected with 1 x 10(7.5) GBS organisms or were killed for determination of lung tis sue levels of PGE(2) and lung and erythrocyte fatty acid composition, Arachidonic acid and PGE(2) levels were significantly higher in the lu ngs of pups in the corn oil group compared with the fish oil group. Fo rty-nine percent of pups in the corn oil group survived the GBS challe nge compared with 79% of pups in the fish oil group (P = 0.0005). Thes e data suggest that the fatty acid composition of pre- and/or postnata l diet affects the neonatal response to immune challenge, which may be due in part to effects upon the synthesis of pro-inflammatory mediato rs.