Jafari A, Fahanik-babaei J, Eliassi A, Saghiri R. Biophysical properties of single potassium channel in the brain mitochondrial inner membrane of male rat with Alzheimer’s disease . Physiol Pharmacol 2013; 17 (1) :1-14
URL:
http://ppj.phypha.ir/article-1-881-en.html
Abstract: (12000 Views)
Introduction: Alzheimer’s disease is a progressive neurodegenerative disorder, characterized by impairment of
memory and changes in behavior and personality. Recent evidence suggests that mitochondrial channels play important
roles in memory disorders. Accordingly, the biophysical properties of a single potassium channel were investigated in
the brain mitochondrial inner membrane of rat with Alzheimer’s disease.
Methods: In the male Wistar rats (220-250 g), Alzheimer’s disease was induced by intracerebroventricular injection
of amyloid beta 1-42 (4μg/μL). After two weeks, the brain mitochondrial inner membranes were extracted. Vesicles
were incorporated into lipid bilayer membranes, and single potassium channel properties were investigated. Also, purity
of the cell fraction was tested by Western blotting. Protein samples were probed with specific antibodies.
Results: Based on our previous data, mitochondrial inner membrane has a potassium channel with a main
conductance 93 pS which was 4-AP sensitive and voltage-insensitive at -50 to +40 mV. In the present study, it was
demonstrated that the channel conductance was increased to 114 pS in Alzheimer’s disease. In addition, the currentvoltage
relationship showed an inward rectification. Western blotting and antibodies directed against various cellular
proteins revealed that the extracted material contains only mitochondria.
Conclusion: Our data showed that the biophysical properties (gating, conductance and activities) of potassium
channel were significantly altered in Alzheimer’s disease. Based on these findings, we propose that the brain
mitochondrial potassium channels are involved in Alzheimer’s disease, and it can be considered as a target for
therapeutic plans.