Exposure to Whole Body Vibration Impairs the Functional Activity of the Energy Producing System in Rabbit Myocardium

Аннотация

Indices of the patterns of energy metabolism in the rabbit myocardium were studied after vertical whole body vibration with an amplitude of 0.5 mm at frequencies of 8 and 44 Hz generated by an industrial unit. The energy dependent reactions of native mitochondria were investigated by a polarographic technique using a Clark-type closed membrane electrode. The metabolic states of mitochondria were modeled in vitro by varying exogenous energy substrates (succinic acid, a mixture of glutamic and malic acids) before and after the effect of the 2,4-dinitrophenol uncoupler of oxidative phosphorylation. Amital or malonate-inhibitory analysis was used to estimate the contributions of nicotinamide dinucleotide and flavinadenin dinucleotide-dependent substrates to the endogenous respiratory activity of mitochondria. The results show that changes in the functional activity of myocardial mitochondria in response to vibration depend on the frequency and duration of exposure and are seen as inhibition of the NAD-dependent link of the respiratory chain and activation of the oxidation system of succinic acid, the ligand of metabotropic purinergic G-protein-conjugated receptor GPR91 from the P2Y-family. Due to a systematic deregulated effect vibration can be used as a factor to model bio-energetic cellular hypoxia, to study vibration phenomena at the level of energy producing systems of tissues and organs and for assessment of the vibroprotective properties of drugs.