Because sensitivity/specificity values were not rigorously reported, we did not include this study in our tables and figures, but clearly

more studies of this type are necessary. Selected abbreviations and acronyms AD Alzheimer’s disease ADRDA Alzheimer’s Disease and Related Disorders Association CAT computed axial tomography CERAD Consortium to Establish a Registry for Alzheimer Disease CT computed tomography DAT dementia of Alzheimer’s Inhibitors,research,lifescience,medical type DLB dementia with Lewy bodies MMSE Mint-Mental State Examination MRI magnetic resonance imaging MTL mesial temporal lobe NINCDS National Institutes of Neurological. Communicative Disorders and Stroke PET positron emission tomography PTC parietotemporal cortex RCBF regional cerebral blood flow SPECT single photon emission computed tomography Notes This work was supported by grants from the John A. Hartford Foundation/American Federation for Aging Research, the Geriatric Education Research Fund of the Fan Fox, and Leslie R. Samuels Foundation to Dr Wollman, and an educational Inhibitors,research,lifescience,medical grant to Dr Prohovnik from Siemens Medical Systems, Inc.
In higher vertebrates that are active during the day (eg, humans,

chicks, and Inhibitors,research,lifescience,medical dogs, but not rats, which are nocturnal), nighttime melatonin secretion is selleck chemicals temporally associated with sleep. Analysis of 24-h urine samples from young and elderly people alike (Figure 1), with or without insomnia, clearly shows a direct correlation between sleep and urinary excretion of 6-sulfatoxymelatonin.1 Subjects with insomnia have a considerably reduced production of melatonin from their pineal gland, which is due to a decrease in the level of the enzyme serotonin Af-acetyltransferase (NAT). Insomnia could therefore Inhibitors,research,lifescience,medical be due to a lack of this NAT enzyme in the pineal gland. Figure 1. Mean 6-sulfatoxymelatonin concentrations over 36 h in young people without sleep disorders (dark blue squares), elderly people without sleep Inhibitors,research,lifescience,medical disorders (light blue squares), independently living elderly patients with insomnia (dark blue circles), elderly … These observations have led several groups to propose treating sleep disorders by administration

of melatonin or melatoninergic compounds, in order to compensate for the lack of melatonin observed in subjects with insomnia. Pineal melatonin almost secretion in humans We have demonstrated that, melatonin is a bioprecursor of hypnotic acetyl metabolites produced by enzymatic acetylation of melatonin and 2-oxomelatonin under the control of acetyltransferases, most probably the NAT enzymes. In 1994, in our laboratory, we developed a specific and highly sensitive gas chromatography-mass spectrometry (GC-MS) method2 to assay, simultaneously and distinct!), plasma concentrations of endogenous melatonin (D0melatonin) and exogenous melatonin (D7-melatonin), in which 7 atoms of H have been substituted by 7 atoms of deuterium.