Effects of intravenous nutrition on lipoprotein metabolism, body composition, weight gain and uremic state in experimental uremia in rats.

The effect on serum lipids, lipoprotein fractions, body composition, weight gain and uremic state of including fat in intravenous nutrition was evaluated in rats with chronic uremia. Uremic rats were given high energy (1385 kJ.kg body weight-1.day-1), low nitrogen (0.6 g N.kg body weight-1.day-1) total parenteral nutrition (TPN) for 12 d with either glucose or glucose plus 30% lipids (Intralipid) as the energy source. Additional uremic and nonuremic groups were fed a standard diet orally. During TPN, serum triglyceride and cholesterol levels were slightly higher in rats fed lipid-based TPN compared to those administered glucose-based TPN or fed the oral diet; but there were no differences 8 h after feeding. The serum lipoprotein fractions showed accumulation of lipids in LDL resulting from the lipid-based TPN but no differences in VLDL. In orally fed uremic rats, more lipids were found in HDL than in the TPN-treated rats. The fractional clearance of the fat emulsion was normal and independent of the nutrition composition. Uremic rats administered lipid-based TPN for 21 d had the same weight gain as orally fed, nonuremic control rats (23 +/- 3 vs. 22 +/- 2%); glucose-based TPN did not support normal growth (10 +/- 1%). Uremic rats fed orally did not grow and retained significantly more body water than TPN-fed uremic rats. In uremic animals, lipid-based TPN also was associated with normal body composition despite significantly lower levels of carnitine in plasma, skeletal muscle and heart tissue.(ABSTRACT TRUNCATED AT 250 WORDS)