D-lysergic acid reduces microtubule-associated tau protein in SH-SY5Y human neuroblastoma cells

1. SH-SY5Y, an adrenergic human neuroblastoma cell line, was used to examine the hypothesis that D-lysergic acid (LSD) affects the metabolism of microtubule-associated tau protein, thus affecting microtubule assembly and the transport of neurotransmitters. 2. After 48 hr treatment LSD (10(-5) and 10(-7) M) decreased 50 kDa tau protein in the membrane (pellet) fraction. The drug (10(-5) M) also decreased in the cytoplasmic (supernatant) fraction. 3. This reduction in tau protein was accompanied by a 65% increase (P < 0.05) in total protein after LSD (10(-7) M) in the cytoplasmic fraction.