In Vivo Study of Transepithelial Potential Difference (TEPD) in Proximal Convoluted Tubules of Rat Kidney by Synchronization Modulation Electric Field

Abstract

Synchronization modulation (SM) electric field has been shown to effectively activate function of Na(+)/K(+) pumps in various cells and tissues, including skeletal muscle cells, cardiomyocyte, monolayer of cultured cell line, and peripheral blood vessels. We are now reporting the in vivo studies in application of the SM electric field to kidney of living rats. The field-induced changes in the transepithelial potential difference (TEPD) or the lumen potential from the proximal convoluted tubules were monitored. The results showed that a short time (20 s) application of the SM electric field can significantly increase the magnitude of TEPD from 1-2 mV to about 20 mV. The TEPD is an active potential representing the transport current of the Na/K pumps in epithelial wall of renal tubules. This study showed that SM electric field can increase TEPD by activation of the pump molecules. Considering renal tubules, many active transporters are driven by the Na(+) concentration gradient built by the Na(+)/K(+) pumps, activation of the pump functions and increase in the magnitude of TEPD imply that the SM electric field may improve reabsorption functions of the renal tubules.

Controlling ERK Activation Dynamics in Mammary Epithelial Cells with Alternating Electric Fields through Microelectrodes

“…Using oscillating EF to tune membrane protein activities has been studied in Na−K pump systems. 29 Specifically, it has been shown that when the frequency of the external EF matches the natural pumping rates of Na−K pumps (∼50 Hz), individual pumps with initially different pumping rates and random pumping phases can be synchronized to generate enhanced transepithelial potential (TEP), due to field-induced energy changes in the ion-transports. However, in our case, the EGFR is not electrogenic and should not be sensitive to ion gradients, and the time scale of the EF pulses (10−20 μs) is obviously much faster in comparison to the operation time of ion pumps.…”

“…Using oscillating EF to tune membrane protein activities has been studied in Na-K pumps systems 29 . Specifically, it has been shown that when the frequency of the external EF matches the natural pumping rates of Na-K pumps (~50 Hz), individual pumps with initially different pumping rates and random pumping phases can be synchronized to generate enhanced transepithelial potential (TEP), due to field-induced energy changes in the ion-transports.…”

Electric field modulation of ERK dynamics shows dependency on waveform and timing

“…If a signal averaging occurs through field-induced variation in the catalytic activity of a membrane protein, such as a simple Michaelis–Menten-type enzyme embedded in a membrane, cell response could be frequency-dependent 33 , 35 . To date, only the Na–K pump system, which is known to be sensitive to the potential and chemical gradient across the membrane, has demonstrated this behavior 36 – 38 . In these cases, EF can thermodynamically offset the energy states of the ion pumps, causing the pumping rate to eventually synchronize with the period of the external driving field.…”

Electrostatic modulation of signaling at cell membrane: Waveform- and time-dependent electric control of ERK dynamics

“…If a signal averaging occurs through field-induced variation in the catalytic activity of a membrane protein, such as a simple Michaelis-Menten-type enzyme embedded in a membrane, cell response could be frequency-dependent 33, 35 . To date, only the Na-K pump system, which is known to be sensitive to the potential and chemical gradient across the membrane, has demonstrated this behavior 36, 37, 38 . In these cases, EF can thermodynamically offset the energy states of the ion pumps, causing the pumping rate to eventually synchronize with the period of the external driving field.…”