Reduced phosphoinositide concentrations in anterior temporal cortex of Alzheimer-diseased brains.

Samples of brain anterior temporal cortex from 17 patients with Alzheimer's disease and 18 age-matched controls have been analysed for myo-inositol and the three phosphoinositides. There was significantly less phosphatidylinositol in the Alzheimer samples (1.36 mumol/g wet weight) than in the controls (2.28 mumol/g). The concentrations of phosphatidylinositol 4-phosphate and phosphatidylinositol 4,5-bisphosphate were also lower in Alzheimer cortex, but differences from the control group were not statistically significant. Free myo-inositol concentrations were 5.11 mumol/g (Alzheimer) and 4.44 mumol/g (control) and again the difference was not significant. The lack of phosphoinositides in Alzheimer temporal cortex may impair receptor function.