Monoglyceryl acetoacetate: a ketone body-carbohydrate substrate for parenteral feeding of the rat.

The monoglyceride of acetoacetate was prepared from diketene and glycerol. The resulting mixture was composed of nearly equal amounts of 1- and 2-monoacetoacetin. This mixture was tested as a parenteral energy substrate by continuous intravenous infusion into the rat. This glyceride provided 71% of the daily energy for 7 consecutive days. Other groups were either fed ad libitum or fed ad libitum and supplemented with intravenous glucose isoenergetic to monoacetoacetin. All three groups had similar daily non-protein energy intake, and the two supplemented groups ate less protein than normal rats. All three groups gained weight similarly although the glucose group tended to gain fastest and the monoacetoacetin group tended to gain slowest. The rates were not significantly different. At the end of 7 days, the glucose group was hyperglycemic and the monoacetoacetin group was hyperketonemic compared to normal fed rats. The only significant differences among the livers was the small size found for the glucose group. Hepatic compositions were similar. It was concluded from these data that intravenous monoacetoacetin can support weight gain in rats and is a potential alternative to glucose as an energy source in parenteral nutrition.