Objective: This study mainly determined the effect of beta-amyloid peptides (Abeta(1-42)) on the ATP-sensitive potassium (K(ATP)) channels of the cultured cortical and hippocampal cholinergic neurons, and further confirmed the protective effect of Diazoxide, which was the specific opener of K(ATP) channels, to the neurons.
Methods: The primary rat cortical and hippocampal cholinergic neurons were cultured. Membrane currents were measured using whole-cell patch-clamp technique.
Results: The data showed that the outward current of neurons significantly decreased after using Abeta(1-42) (P<0·05), and that the outward current of decreased did not change after given Diazoxide again (P>0·05) compared with control. However, after being pretreated with Diazoxide for 1 hour before using Abeta(1-42), this phenomenon did not exist; that is, the membrane current of the neurons did not change when we give Abeta(1-42) after pretreatment with Diazoxide (P>0·05).
Conclusions: It is concluded that Abeta(1-42) inhibits the openings of the K(ATP) channels, while this inhibitory action can be removed by pretreatment with Diazoxide. It is indicated that the opening of K(ATP) channels may play a potential neuroprotective role in antineurotoxicity of Abeta(1-42), and the application of Diazoxide in small dose may be helpful in the treatment of Abeta(1-42) neurotoxicity.