[Reversing effect of histamine on neurotoxicity induced by beta-amyloid1-42].

Objective: To investigate the effects of histamine on the neurotoxicity induced by beta-amyloid(1-42)(Abeta42) in rat phaeochromocytoma (PC12) cells.

Methods: The in vitro model of Alzheimer's disease was constructed with A beta42-treated PC12 cells. Cell morphology and MTT assay were used to evaluate the cell toxicity and histamine effects.

Carnosine protects against NMDA-induced neurotoxicity in differentiated rat PC12 cells through carnosine-histidine-histamine pathway and H(1)/H(3) receptors.

Since the histidine-containing dipeptide carnosine (beta-alanyl-L-histidine) is believed to have many physiological functions in the brain, we investigated the neuroprotective effects of carnosine and its mechanisms of action in an in vitro model of neurotoxicity induced by N-methyl-d-aspartate (NMDA) in differentiated PC12 cells. Pretreatment with carnosine increased the viability and decreased the number of apoptotic and necrotic cells measured by MTT and Hoechst 33342 and propidium iodide (PI) double staining assays. Carnosine also can inhibit the glutamate release and increase HDC activity and the intracellular and extracellular contents of carnosine, histidine and histamine detected by high-performance liquid chromatography (HPLC).