Comparison of acetate-1-14C metabolism in uremic and nonuremic dogs

Acetate-1-14C was infused into six anephric uremic and six anephric nonuremic dogs during a 4-hr hemodialysis against a standard acetate containing (39.5 mM) dialysis solution. Arterial acetate (nonradioactive) levels achieved a steady state by the end of dialysis indicating that the maximum rate of acetate metabolism had not been exceeded. The mean arterial acetate level at the end of dialysis was 2.6 mM in both groups of dogs. Acetate disappearance after the cessation of dialysis followed first order kinetics with a mean half-life of 3.8 +/- 0.5 min in the uremic and 3.7 +/- 0.5 min in the nonuremic dogs. Most of the infused acetate-1-14C was metabolized to 14CO2 within 8 hr after dialysis. An average of 84 and 71% of the infused acetate-1-14C was metabolized to 14CO2 in the uremic and nonuremic dogs, respectively. Small but significant amounts of radioactivity were incorporated into lipids of plasma and other tissues. Incorporation of radioactivity into total lipids of liver, omental fat, and sciatic nerve was significantly greater in the uremic as compared to the nonuremic dogs. Incorporation of radioactivity into total lipids of heart, aorta, and plasma was the same in both groups of dogs.