4Hz mechanical vibration relieves pain through Na+/K+-ATPase α3 isoform-dependent brain tissue dehydration

In this work the effect of 4Hz 30dB horizontal mechanical vibration (MV) on thermal pain threshold, hydration and [3H]-ouabain binding in brain and heart muscle tissues of rats was studied. It was revealed that 4Hz MV treatment for 10 minutes increased pain threshold, which was accompanied by brain and heart muscle tissue dehydration. In vitro state, hydration of brain and heart muscle tissues of sham animals was increased, while in 4Hz MV-treated animals the increase of brain tissue hydration was more pronounced and heart muscle tissues were dehydrated. The fact that 4Hz MV treatment also impacted heart muscle tissue hydration indicates that 4Hz MV effect on brain and heart muscle tissues is realized through a common messenger circulating in blood. The incubation of brain and heart muscle tissues in PS containing 10-4M and 10-9M ouabain led to tissue hydration in sham and 4Hz MV-treated animals. However, tissues of 4Hz MV-treated animals were less hydrated, and this hydration was accompanied by the decrease and increase of membrane receptors’ affinity at 10-4M and 10-9M ouabain concentrations, respectively. Based on the obtained data, it is suggested that pain-relieving effect of 4Hz MV is due to α3 isoform-dependent brain tissue dehydration.