Preliminary Characterization of Mitochondrial ATP-sensitive Potassium Channel (MitoKATP) Activity in Mouse Heart Mitochondria

• Main Author: Aachi, Venkat Raghav
• Format: Others
• Published: PDXScholar 2009
• Subjects: Coronary heart disease > Research; Coronary heart disease > Prevention; Potassium channels; Heart > Physiology; Mitochondria; Biology; Cardiovascular Diseases
• Online Access: https://pdxscholar.library.pdx.edu/open_access_etds/1667; https://pdxscholar.library.pdx.edu/cgi/viewcontent.cgi?article=2666&context=open_access_etds

Myocardial ischemia, infarction, heart failure and arrhythmias are the manifestations of coronary artery disease. Reduction of ischemic damage is a major concern of cardiovascular biology research. As per recent studies, the mitochondrial ATP-sensitive potassium channel (mitoKATP) opening is believed to play key role in the physiology of cardioprotection, protection against ischemia-reperfusion injury or apoptosis. However, the structural information of mitoKATP is not precisely known. Elucidating the structural integrity and functioning of the mitoKATP is therefore a major goal of cardiovascular biology research. The known structure and function of the cell ATP-sensitive potassium channel (cellKATP) is functional in interpreting the structural and functional properties of mitoKATP. The primary goal of my research was to characterize the activity of mitoKATP in the isolated mitochondria from the control mouse heart. The mitoKATP activity, if preliminarily characterized in the control strains through the light scattering technique, then the structure of the channel could possibly be established and analyzed by means of the transgenic model and with the help of immunological techniques such as western blotting and immunoflorescence. With this experimental model it was possible to demonstrate that the mitoKATP activity in control mouse heart mitochondria is activated by potassium channel openers (KCOs) such as diazoxide and cromakalim and activators of mitoKATP such as PMA (phorbol12 myristate-13-acetate), and inhibited by KATP inhibitors such as glibenc1amide and 5-hydroxydecanoate (5 HD). It was evident that the KATP activity in mouse heart mitochondria was comparable to that exhibited by the rat heart mitochondria. The various selective and non-selective activators and inhibitors of the channel elicited their activity at a similar concentration used for the rat heart mitochondria. The results were reproducible in five independent experiments for each combination, further reinforcing the significance of existing channel activity in the mouse heart mitochondria.