Lipid-free total parenteral nutrition and macrophage function in rats
M. S. Nussbaum, S. J. Li, C. K. Ogle, F. S. Zhang, O. Zamir, R. H. Bower and J. E. Fischer
Department of Surgery, University of Cincinnati Ohio Medical Center 45267.
Certain lipids are immunosuppressive when used for nutritional support,
while other lipids and nutritional additives may enhance immunologic
function. We hypothesized that total parenteral nutrition (TPN) may be
immunosuppressive irrespective of lipids. Twenty-four rats underwent
central vein catheterization and received either intravenous saline
solution and oral chow or TPN alone. At 7 or 14 days, the animals were
killed. Splenic and bone marrow macrophages were isolated and cultured in
either M199 medium alone or were stimulated with Escherichia coli
lipopolysaccharide. The supernatants were tested for prostaglandin E2 and
C3. The splenic prostaglandin E2 levels were significantly higher in the
TPN group following lipopolysaccharide stimulation at 7 days but not at 14
days. Administration of TPN to rats, even without lipids, may be
immunosuppressive through the release of prostaglandin E2 from splenic
macrophages following a septic challenge. This effect appears to be
abolished after 14 days of TPN infusion.
