DeBruin K A, Krassowska W
Department of Biomedical Engineering and Center for Emerging Cardiovascular Technologies, Duke University, Durham, North Carolina 27708-0281 USA.
Biophys J. 1999 Sep;77(3):1213-24. doi: 10.1016/S0006-3495(99)76973-0.
This study develops a model for a single cell electroporated by an external electric field and uses it to investigate the effects of shock strength and rest potential on the transmembrane potential V(m) and pore density N around the cell. As compared to the induced potential predicted by resistive-capacitive theory, the model of electroporation predicts a smaller magnitude of V(m) throughout the cell. Both V(m) and N are symmetric about the equator with the same value at both poles of the cell. Larger shocks do not increase the maximum magnitude of V(m) because more pores form to shunt the excess stimulus current across the membrane. In addition, the value of the rest potential does not affect V(m) around the cell because the electroporation current is several orders of magnitude larger than the ionic current that supports the rest potential. Once the field is removed, the shock-induced V(m) discharges within 2 micros, but the pores persist in the membrane for several seconds. Complete resealing to preshock conditions requires approximately 20 s. These results agree qualitatively and quantitatively with the experimental data reported by Kinosita and coworkers for unfertilized sea urchin eggs exposed to large electric fields.
本研究建立了一个受外部电场作用的单细胞电穿孔模型，并用其研究电击强度和静息电位对细胞周围跨膜电位V(m)和孔密度N的影响。与电阻 - 电容理论预测的感应电位相比，电穿孔模型预测整个细胞内V(m)的幅度更小。V(m)和N关于赤道对称，在细胞两极具有相同的值。较大的电击不会增加V(m)的最大幅度，因为会形成更多的孔来分流跨膜的过量刺激电流。此外，静息电位的值不影响细胞周围的V(m)，因为电穿孔电流比支持静息电位的离子电流大几个数量级。一旦电场去除，电击诱导的V(m)在2微秒内放电，但孔在膜中持续存在几秒。完全重新密封到电击前的状态大约需要20秒。这些结果在定性和定量上与木下及其同事报道的未受精海胆卵暴露于强电场的实验数据一致。
