Transport regulates nutrient availability in the brain, and many pathways of brain amino acid metabolism are influenced by precursor supply. Therefore, amino acid transport through the blood-brain barrier (BBB) plays an important rate-affecting role in brain metabolism. Information on the Km of BBB amino acid transport provides the quantitative basis for understanding the physiological importan...

Abstract The association of sleep and rest-activity rhythms (RAR) with metabolic health is not fully understood. Previous studies have identified multiple metabolite markers in amino acid lipid pathways associated various characteristics sleep. However, most the used self-reported sleep, limited examined 24-hour RAR profiles, a more complete picture activity. We studied 950 older men measured m...

Genetic disorders of amino acid and fatty acid metabolism can be detected with tandem mass spectrometry (MS/MS). MS/MS screening of mice subjected to chemical mutagenesis (see the related article beginning on page 434) defined a new disorder of branched-chain amino acid metabolism resembling human maple syrup urine disease. This approach has general application to the discovery of gene function...