Abstract
Acute lung injury (ALI) and sepsis remain major challenges in critical care. While a massive inflammation determines early sepsis, apoptosis of lymphocytes is a hallmark of late sepsis. Lipid emulsions (LE) based on soybean oil (SO) are used in critically ill to maintain caloric intake. Fish oil (FO) based LE are considered as alternative with immunmodulatory impact. We investigated the effects of LE in a murine model of ALI.
Mice were infused with SO, FO or NaCl. 24h after intratracheal instillation of 10μg lipopolysaccharid (LPS), a bronchoalveolar lavage (BAL) was performed to determine numbers of leukocytes, protein and cytokines. Lymphocytes were isolated from spleen and apoptosis was determined by FACS.
LPS induced a massive invasion of leukocytes into the airspace compared to unstimulated controls. Infusion of SO amplified whereas FO attenuated the rise. Both, protein and TNF exhibited a LPS-induced rise which was further increased by SO. Infusion of FO reduced protein as well as TNF after LPS.
Before LPS, infusion of SO induced a significant rise in apoptosis of lymphocytes. After LPS, a reduced number of lymphocytes accompanied with a rise in apoptosis were detected in all groups with FO infused mice showing significantly less apoptosis compared to SO.
In a murine model of ALI the choice of lipid emulsions is able to influence inflammatory parameters. Induction of ALI is paralleled by reduced lymphocytes with increased apoptosis in the spleen. SO leads to massive apoptosis in lymphocytes even before ALI. Infusion of FO attenuated the rise in ALI-induced apoptosis. Modulating the lipid emulsions used for nutrition may be relevant for critically ill and may have impact on outcome.
- © 2011 ERS
