Matsuyama S S, Yamaguchi D T, Vergara Y, Jarvik L F
Psychogeriatric Laboratory (B151R), West LA VAMC, Los Angeles, CA 90073, USA.
Dementia. 1995 Sep-Oct;6(5):241-4. doi: 10.1159/000106953.
Potassium (K+) channel dysfunction in fibroblasts was recently proposed as a potential diagnostic marker for Alzheimer disease (AD). We utilized a microspectrofluorometric method with Fura-2AM to measure intracellular free calcium ([Ca2+]i) following depolarization with the K+ channel blocker tetraethylammonium (TEA) in seven AD and seven control fibroblast cultures. Contrary to our expectation, 43% of the AD and 36% of the control fibroblast plated coverglasses responded with an increase in [Ca2+]i on addition of 100 mM TEA. The data suggest that the TEA-elicited [Ca2+]i response is not a useful AD screening test.
