Parenteral feeding at two hypocaloric levels for comparison of glucose-glycerol mixture with the monoglyceride of acetoacetate on urinary nitrogen losses of the rat.

The monoglyceride of acetoacetate (monoacetoacetin) is a synthetic compound that might serve to reduce the glucose contribution to nonprotein energy in total parenteral nutrition provided it is an effective nutritional source. This study compared monoacetoacetin and glucose-glycerol mixtures as energy in hypocaloric, parenteral feeding of the rat. Four groups of rats were infused with approximately 425 mg N/day along with 11 or 21 kcal/day supplied either by monoacetoacetin or the glucose-glycerol mixture. Body weight and urinary nitrogen were followed for 7 days, and leucine kinetics was measured on day 7. At 11 or 21 kcal/day, rats infused with the monoacetoacetin or the glucose-glycerol mixture had similar body weight losses, urinary nitrogen losses, leucine flux and leucine oxidation rates. When rats receiving the same energy substrate at 11 or 21 kcal/day were compared, the rats receiving the 21 kcal/day by vein lost less body weight and less urinary nitrogen and had a smaller leucine flux. The leucine oxidation rate was unchanged. These data demonstrate that alterations in nitrogen parameters are dependent on the quantity of energy but are independent of the source of energy when monoacetoacetin and glucose-glycerol mixtures are compared. Monoacetoacetin interacts with nitrogen metabolism in healthy rats as effectively a glucose-glycerol mixtures at the hypocaloric levels studied.