INFLUENCE OF THE EFFECTORS OF MITOCHONRIAL ATP DEPENDENT
POTASSIUM CHANNEL OF DIAZOXIDE AND GLYBENCLAMIDE ON HYDRODYNAMIC
DIAMETER AND MEMBRANE POTENTIAL OF THE MITOCHONDRIA MYOMETRIUM
Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
Mitochondrial ATP-sensitive potassium channel (mitoKATP) is a main factor of regulation of K+ exchange in mitochondria. Using photon correlation spectroscopy we have shown diazoxide-induced increase of hydrodynamic diameter of mitochondrial particles from the rat myometrium. Selective channel blocker glybenclamide partially eliminates this effect.
By means of Rhodamine-123 fluorescence it was shown that activation of ATP-sensitive K+-channel in mitochondria caused partial depolarization of the mitochondrial membrane. This effect was absolutely blocked by glybenclamide. In the presence of valinomycine and diazoxide together, depolarization also was detected, but in this case glybenclamide failed to restore mitochondrial potential.
Thus, activation of mitoKATP from the rat myometrium causes the increase of the hydrodynamic diameter of organelles and partial depolarization of the inner membrane.
Key words: mitochondrial ATP-sensitive potassium channel, diazoxide, mitochondrial potential.
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