MODULATION OF AMYLOID PRECURSOR PROTEIN PROCESSING BY COMPOUNDS WITH VARIOUS MECHANISMS OF ACTION - DETECTION BY LIQUID-PHASE ELECTROCHEMILUMINESCENT SYSTEM

beta-Amyloid peptide (A beta) is a major component of senile plaques f ormed in the brain of Alzheimer disease patients. We describe here a n ew method of quantitating A beta in biological material using liquid p hase electrochemiluminescent system (LPECL). We used both enzyme-linke d immunosorbent assay (ELISA) and LPECL methods to measure A beta and APPs alpha levels in conditioned medium of beta-amyloid precursor prot ein (APP)-transfected CHO cells treated with known modulators of APP p rocessing, and in CSF and plasma of guinea pigs. Our results indicate that while maintaining the accuracy and sensitivity Of ELISA, LPECL is a significantly faster and less labor-intensive method for measuring of A beta and APPs alpha levels in biological fluids. (C) 1998 Elsevie r Science B.V. All rights reserved.