Phospholipase A2 activity is decreased selectively in the hippocampus of aged apolipoprotein E deficient mice.
Because apolipoprotein E (ApoE) deficient mice have cognitive deficits (Neurosci. Lett., 199 (1995) 1-4; Neuroscience, 92 (1999) 1273-1286; Brain Res., 752 (1997) 189-196) that may involve decreased phospholipase A(2) (PLA(2)) activity (Neuroscience, 92 (1999) 1273-1286), striatal, hippocampal, and parieto-temporal PLA(2) activity was measured in cytosol from 3 and 20-month-old ApoE deficient and control mice. Samples were homogenized and cytosol prepared by ultracentrifugation. PLA(2) activity in each cytosolic fraction was measured in triplicate using a continuous fluorometric assay (J. Neurosci. Methods (2000) in press). In 3-month-old animals, there was a trend for decreased hippocampal PLA(2) activity between groups. In 20-month-old animals, hippocampal PLA(2) activity was significantly (P=0.0304) decreased nearly 20% in ApoE deficient mice as compared to age-matched control mice. No differences were found in other brain regions, although activity in the striatal samples were nearly 65% less than in the other two regions.
Patrick
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CB
Section on Brain Physiology and Metabolism, National Institute on Aging, National Institutes of Health, Building, 10, Room 6C103, 10 Center Drive MSC 1582, Bethesda, MD 20892, USA.
Krzywkowski
P
P
Ramassamy
C
C
Poirier
J
J
Rapoport
S I
SI
Murphy
E J
EJ
D000375:Aging / Q000235:genetics / Q000502:physiology*; D000818:Animals; D001057:Apolipoproteins E / Q000172:deficiency* / Q000235:genetics* / Q000502:physiology; D016718:Arachidonic Acid / Q000378:metabolism; D003600:Cytosol / Q000201:enzymology / Q000502:physiology; D004789:Enzyme Activation / Q000502:physiology; D006624:Hippocampus / Q000201:enzymology* / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010741:Phospholipases A / Q000037:antagonists & inhibitors / Q000378:metabolism*; D054467:Phospholipases A2
D001057:Apolipoproteins E; D016718:Arachidonic Acid; D010741:Phospholipases A; D054467:Phospholipases A2