Reduced phospholipid breakdown in Alzheimer's brains: a 31P spectroscopy study.
BACKGROUND
Abnormalities of membrane phospholipid metabolism have been described in Alzheimer's disease (AD). We investigated, with the aid of (31)P magnetic resonance spectroscopy, the in vivo intracerebral availability of phosphomonoesters (PME) and phosphodiesters (PDE) in patients with AD.


METHODS
Eighteen outpatients with mild or moderate probable AD and 16 nondemented elderly volunteers were assessed with the Cambridge Examination for Mental Disorders of the Elderly (CAMDEX) and its cognitive subscale of the CAMDEX schedule (CAMCOG). Scans were performed on a 1.5 T magnetic resonance imager addressing a 40-cm(3) voxel in the left prefrontal cortex. Main outcome measures were mean relative peak areas of PME and PDE, which provide an estimate of membrane phospholipid metabolism.


RESULTS
PME resonance and the PME/PDE ratio were increased in AD patients as compared to controls (p<0.05). PME was negatively correlated with global cognitive performance as shown by the Mini-Mental State Examination (r(s)=-0.36, p=0.05) and CAMCOG scores (r(s)=-0.49, p=0.007), as well as with discrete neuropsychological functions, namely, memory (r(s)=-0.53, p=0.004), visual perception (r(s)=-0.54, p=0.003), orientation (r(s)=-0.36, p=0.05), and abstract thinking (r(s)=-0.48, p=0.01).


CONCLUSIONS
We provide evidence of reduced membrane phospholipid breakdown in the prefrontal cortex of mild and moderately demented AD patients. These abnormalities correlate with neuropsychological deficits that are characteristic of AD.
Forlenza
Orestes V
OV
Laboratory of Neuroscience (LIM-27) Department and Institute of Psychiatry, Faculty of Medicine, University of São Paulo, Rua Doutor Ovídio Pires de Campos 785, 05403-010, São Paulo, SP, Brazil.
Wacker
Priscilla
P
Nunes
Paula V
PV
Yacubian
Juliana
J
Castro
Claudio C
CC
Otaduy
Maria C G
MC
Gattaz
Wagner F
WF
D000368:Aged; D000544:Alzheimer Disease / Q000378:metabolism*; D001921:Brain / Q000378:metabolism*; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D010741:Phospholipases A / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism*
D010743:Phospholipids; D010741:Phospholipases A