Mitochondria from rat uterine smooth muscle possess ATP-sensitive potassium channel

Abstract EN

The objective of this study was to detect ATP-sensitive K+ uptake in rat uterine smooth muscle mitochondria and to determine possible effects of its activation on mitochondrial physiology.

By means of fluorescent technique with usage of K+-sensitive fluorescent probe PBFI ( potassium-binding benzofuran isophthalate) we showed that accumulation of K ions in isolated mitochondria from rat myometrium is sensitive to effectors of KATP-channel (ATP-sensitive K+- channel) – ATP, diazoxide, glibenclamide and 5HD (5-hydroxydecanoate).

Our data demonstrates that K+ uptake in isolated myometrium mitochondria results in a slight decrease in membrane potential, enhancement of generation of ROS (reactive oxygen species) and mitochondrial swelling.

Particularly, the addition of ATP into incubation medium led to a decrease in mitochondrial swelling and ROS production, and an increase in membrane potential.

These effects were eliminated by diazoxide.

If blockers of KATP-channel were added along with diazoxide, the effects of diazoxide were removed.

So, we postulate the existence of KATP-channels in rat uterus mitochondria and assume that their functioning may regulate physiological conditions of mitochondria, such as matrix volume, ROS generation and polarization of mitochondrial membrane.