Amyloid beta peptides mediate hypoxic augmentation of Ca(2+) channels.

Clinical studies indicate that neurodegeneration caused by Alzheimer's amyloid beta peptide (AbetaP) formation can be triggered or induced by prolonged (chronic) hypoxia. Here, we demonstrate that 24-h culture of PC12 cells in 10% O(2) leads to induction of a Cd(2+)-resistant Ca(2+) influx pathway and selective potentiation of L-type Ca(2+) current. Both effects were suppressed or prevented by a monoclonal antibody raised against the N'-terminus of AbetaP, and were fully mimicked by AbetaP(1-40 and) AbetaP(1-42), but not by AbetaP(40-1). Potentiation of L-type currents was also induced by exposure to AbetaP(25-35). Our results indicate that hypoxia induces enhancement of Ca(2+) channels, which is mediated by increased AbetaP formation.