Phospholipase A(2) activity is decreased selectively in the hippocampus ofaged apolipoprotein E deficient mice

Because apolipoprotein E (ApoE) deficient mice have cognitive deficits (Neu rosci. Lett., 199 (1995) 1-4; Neuroscience, 92 (1999) 1273-1286; Brain Res. , 752 (1997) 189-796) 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-mont h-old ApoE deficient and control mice. Samples were homogenized and cytosol prepared by ultracentrifugation. PLA(2) activity in each cytosolic fractio n was measured in triplicate using a continuous fluorometric assay (J. Neur osci. 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 a nimals, hippocampal PLA(2) activity was significantly (P = 0.0304) decrease d nearly 20% in ApoE deficient mice as compared to age-matched control mice . No differences were found in other brain regions, although activity in th e striatal samples were nearly 65% less than in the other two regions. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.