Utilization of Intralipid in septic rats: effects of sepsis on the clearance of exogenous fat emulsion from various organs.

Abstract

The rats were used for the study of the effects of sepsis on the utilization of exogenous fat emulsion. The studies were carried out by measuring the rate and the pattern of clearance of intravenously-administered 14C-Intralipid from the plasma, liver, spleen, kidney, and muscle of control and septic rats. Plasma clearance of the exogenous fat measured for 14C at 30, 60, 90, 120, 360 min (n = 5) after intravenous injection revealed that the clearance was retarded by sepsis. In the liver, the initial 14C uptake was much greater in the septic rats than those in the control group (34.8 +/- 3.6% vs 14.4 +/- 1.6%, p less than 0.01). Six hr after injection, as high as 19.6 +/- 2.4% of the injected dose was detected in the liver of the septic rats, but the control rats had only 4.4 +/- 0.8%. In spleen, kidney, and muscle, however, both the 14C uptake and the rate of its clearance were greater for the control rats than those of the septic group. The increase in the amount of liver uptake of the exogenous fat by the septic rat and the retained large amount of the fat may account for the decreased plasma clearance and the decrease in its subsequent utilization by other organs and tissues. Significant increase in liver contents of total lipid and triglyceride with a decrease in nonesterified fatty acid (NEFA) at the end of a 6-hr period in septic rats suggest that accumulation of fat in the liver may be a result of impaired triglyceride hydrolysis, possibly due to suppressed lipoprotein lipase activity.