Tag Archives: Ca ions

Protective effects of potassium transport in mitochondria from rat myometrium under activation of mitochondrial permeability transition pore

O. B. Vadzyuk

Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
e-mail: olga_vadzyuk@hotmail.com

We demonstrated using PBFI K+-sensitive fluorescent probe an enhancement of both components of K+-cycle – the ATP-sensitive K+-uptake and quinine-sensitive K+/H+-exchange – under the Ca2+ induced opening­ of mitochondrial permeability transition pore (MPTP) in rat myometrium mitochondria. Addition of CaCl2 (100 μM) to K+-free medium results in the enhancement of reactive oxygen species (ROS) production, which was eliminated by cyclosporine A. Addition of CaCl2 to K+-rich medium did not increase the rate of ROS production, but blocking of mitoK+ATP-channels with glybenclamide (10 μM) increased production of ROS. We conclude that K+-cycle exerts a protective influence in mitochondria from rat myometrium by regulation of matrix volume and rate of ROS production under the condition of Ca2+-induced MPTP.