Several laboratories have investigated monocarboxylate transport in a variety of cell types. The characterization of the cloned transporter isoforms in a suitable expression system is nevertheless still lacking. H+/monocarboxylate co-transport was therefore investigated in monocarboxylate transporter 1 (MCT1)-expressing Xenopus laevis oocytes by using pH-sensitive microelectrodes and [14C]lacta...

The efficacy of parenteral nutrition could be improved by finding a more effective energy source. Esters of short-chain fatty acids have exhibited some promise as alternatives to glucose. The present study reports on two new esters and one amide, each containing acetoacetate as the organic acid. The three compounds: glyceryl bisacetoacetate, N-2',3'-dihydroxypropyl-3-oxo-butanamide (1-acetoacet...

1. A spectrophotometric direct-reading assay for measurements of beta-oxidation by intact mitochondria is described. The procedure relies on the ability of ferricyanide to trap reducing equivalents generated by the acyl-CoA dehydrogenases (EC 1.3.99.3). The reduction of ferricyanide was recorded by using a dual-wavelength spectrophotometer. 2. Oxaloacetate or acetoacetate was used to stimulate ...

The picture of L-tyrosine metabolism obtained from isotope experiments and other studies on intact animals is still incomplete. Either p-hydroxyphenylpyruvate or 2:5-dihydroxyphenylalanine may be the first intermediate, since either could form the second postulated intermediate, 2:5-dihydroxyphenylpyruvate (Neubauer, 1909), and both are converted to homogentisic acid by alcaptonurics (Neuberger...

AS many as 40% of patients who present with traumatic brain injury have positive blood–alcohol test results. Small, portable devices designed to measure ethanol concentrations in exhaled breath have been used extensively by law enforcement officials to estimate blood– alcohol measurements accurately in drunk drivers. In the case of patients who have an altered mental status or who do not emerge...

The chemical synthesis and properties of L-carnitine esters of P-ketopalmitic acid, /3-hydroxypslmitic acid, and ~ranstr,P-unsaturated palmitic acid are described. Isolated rat liver mitochondria oxidize the carnitine esters of these acids more efficiently than the free acids as judged by acetoacetate production and oxygen uptake. Rat liver mitochondrial extracts catalyze the conversion of palm...

Specifically 14C-labeled palmitic acids were perfused through livers and incubated with slices of kidneys from rats in diabetic ketosis. The distribution of 14C in the hydroxybutyric acid formed was determined. In liver, the ratio of incorporation of 14C from [13-14C]palmitic acid into carbon 1 to carbon 3 of the hydroxybutyric acid was the same as the ratio in carbon 2 to carbon 4 from [6-14C]...

In this study, the metabolome of Ruditapes decussatus, an economically and ecologically important marine bivalve species widely distributed in the Mediterranean region, was characterized by using proton Nuclear Magnetic Resonance (¹H-NMR) spectroscopy. Significant seasonal variations in the content of carbohydrates and free amino acids were observed. The relative amounts of alanine and glycine ...

The regulation of the pyruvate dehydrogenase multienzyme complex was studied in the isolated perfused rat heart. Because 95% of the “CO2 produced as a result of the decarboxylation of [l-‘4C]pyruvate occurs via pyruvate dehydrogenase in the heart, the rate of 14COz production from infused [l-‘4C]pyruvate was utilized as the monitor of the metabolic flux through this enzyme complex. In contrast ...

Studies in man have shown that the episodic release of growth hormone (GH) is infrequent and erratic, and unlike that in the rat does not appear to have discernible ultradian periodicities. However, these observations in nonfasted subjects may be invalid since mixed nutrients have unpredictable effects on GH release. Moreover, in the fed state basal GH levels are frequently undetectable, thus r...