acids and ketone bodies in the circulation, and there is a need to conserve glucose because of the relatively low carbohydrate content of the milk (for review see Williamson, 1985). During this period of development, brown adipose tissue has a vital role in thermogenesis, and the level of GDP-binding to brown-fat mitochondria is considerably increased (Sundin & Cannon, 1980). The weight of inte...

The effects of carnitine on the metabolism of palmitoylcarnitine were studied by using isolated rat liver mitochondria. Particular attention was given to carnitine acyltransferase-mediated interactions between carnitine and the mitochondrial CoA pool. Carnitine concentrations less than 1.25mm resulted in an increased production of acetylcarnitine during palmitoylcarnitine oxidation. Despite thi...

1. The rates of formation of acetoacetate and beta-hydroxybutyrate by the isolated perfused rat liver were measured under various conditions. 2. The rates found after addition of butyrate, octanoate, oleate and linoleate were about 100mumoles/hr./g. wet wt. in the liver of starved rats. These rates are much higher than those found with rat liver slices. 3. The differences between the rates give...

Concentrations of acetoacetate and P-hydroxybutyrate and their specific radioactivities were shown to be assayable directly in plasma of the rat without the need for prior deproteinization. By utilizing this technique ketone body turnover was estimated in the isotopic steady state and after the single injection of radioactive acetoacetate or P-hydroxybutyrate. While difEculties exist in both ty...

Protein modification (sometimes known as crosslinking) often requires two or more steps to affix a small molecule irreversibly. Two-step reductive alkylation of the enzyme rabbit muscle aldolase with ethyl 3-C-acetoacetate and sodium cyanoborohydride attaches less radioactivity than with cyanoborohydride omitted. The C level incorporated into aldolase corresponds to only about 15–30 modified pr...

The effect of hyperphenylalaninaemia on the metabolism of ketone bodies in vivo and in vitro by developing rat brain was investigated. The incorporation in vivo of [14C]acetoacetate into cerebral lipids was decreased by both chronic (for 3 days) and acute (for 6h) hyperphenylalaninaemia induced by injecting phenylalanine into 1-week-old rats. In studies in vitro it was observed that the incorpo...

beta-hydroxybutyrate and acetoacetate as well as lactate and pyruvate are intermediary metabolites normally present in blood. The beta-hydroxybutyrate/acetoacetate ratio is an expression of the mitochondrial oxido-reduction state. This ketone body ratio can provide a clue to diagnosis and metabolic status in congenital errors of the electron transport chain and pyruvate metabolism. The standard...

backgrounds: subclinical ketosis can cause greater economic loss due to a lack of clinical symptoms. objectives: the present study was aimed to design a chemical method for measuring serum ketone bodies in the affected subclinical cows. methods: acetoacetate concentrations were measured using a nitroprusside reaction and b-hydroxy butyric acid (bhba) which was oxidized to acetoacetate using nan...

1. Commercially available coenzyme A preparations were found to contain sufficient amounts of glutathione so that in the reaction with diketene significant quanties of acetoacetyl glutathione were formed. Unless allowances are made for this, significant errors in the interpretation of results can be made because liver mitochondria contain a very active acetoacetyl glutathione hydrolase. 2. Puri...