Pathological mechanism
beta-Amyloid potentiates Ca influx through L-type Ca channels
  • Dendritic Hypothesis - Ca++ currents Show Other
  • Amyloid beta protein potentiates Ca2+ influx through L-type voltage-sensitive Ca2+ channels: a possible involvement of free radicals. Show Other
The role of the voltage-sensitive Ca2+ channel (VSCC) in beta (25-35) neurotoxicity was examined using rat cultured cortical and hippocampal neurons. When L-type VSCCs were blocked by application of nimodipine, beta (25-35) neurotoxicity was attenuated, whereas application of omega-conotoxin GVIA (omega-CgTX-GVIA) or omega-agatoxin IVA (omega-Aga-IVA), the blocker for N- or P/Q-type VSCCs, had no effects. Whole-cell patch-clamp studies indicated that the Ca2+ current density of beta (25-35)-treated neurons is about twofold higher than that of control neurons. Also, beta (25-35) increased Ca2+ uptake, which was sensitive to nimodipine. The 2', 7'-dichlorofluorescin diacetate assay showed the ability of beta (25-35) to produce reactive oxygen species. Nimodipine had no effect on the level of free radicals. In contrast, vitamin E, a radical scavenger, reduced the level of free radicals, neurotoxicity, and Ca2+ uptake. These results suggest that beta (25-35) generates free radicals, which in turn, increase Ca2+ influx via the L-type VSCC, thereby inducing neurotoxicity. (Ueda K et al. 1997)
Exclude - Neurotoxicity
Other categories referring to beta-Amyloid potentiates Ca influx through L-type Ca channels
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Last Time: 10/27/2017 9:48:16 PM
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