Hemin inhibits the large conductance potassium channel in brain mitochondria: A putative novel mechanism of neurodegeneration.

Hemin inhibits the large conductance potassium channel in brain mitochondria: A putative novel mechanism of neurodegeneration. Exp Neurol. 2014 Apr 30; Authors: Augustynek B, Kudin AP, Bednarczyk P, Szewczyk A, Kunz WS Abstract Intracerebral hemorrhage (ICH) is a pathological condition that accompanies certain neurological diseases like hemorrhagic stroke or brain trauma. Its effects are severely destructive to the brain and can be fatal. There is an entire spectrum of harmful factors which are associated with the pathogenesis of ICH. One of them is a massive release of hemin from the decomposed erythrocytes. It has been previously shown, that hemin can inhibit the large-conductance Ca(2+)-regulated potassium channel in the plasma membrane. However, it remained unclear whether this phenomenon applies also to the mitochondrial large-conductance Ca(2+)-regulated potassium channel. The aim of the present study was to determine the impact of hemin on the activity of the large conductance Ca(2+)-regulated potassium channel in the brain mitochondria (mitoBKCa). In order to do so, we have used a patch-clamp technique and shown that hemin inhibits mitoBKCa in human astrocytoma U-87 MG cell line mitochondria. Since opening of the mitochondrial potassium channels is known to be cytoprotective, we have elucidated whether hemin can attenuate some of the beneficiary effects of potassium channel opening. We have studied the effect of hemin on reac...
Source: Experimental Neurology - Category: Neurology Authors: Tags: Exp Neurol Source Type: research