Sta Iglesia D D, Cragoe E J, Vanable J W
Department of Biologiccal Sciences, Purdue University, West Lafayette, Indiana 47907, USA.
J Exp Zool. 1996 Jan 1;274(1):56-62. doi: 10.1002/(SICI)1097-010X(19960101)274:1<56::AID-JEZ6>3.0.CO;2-E.
There is convincing evidence that endogenous electric fields are necessary for normal wound epithelization, but it is unclear whether normal epithelization rates can be accelerated increasing normal field strengths. Although we confirmed that normal lateral fields are required for normal Notophthalmus viridescens epithelization rates, significant increases in epithelization were not achieved by increasing normal field strengths with direct current. With increases of less than 50%, epithelization rates were slightly increased. When the field strengths were augmented by 50%, epithelization was significantly retarded. This pattern was also observed when we applied direct current to wounds whose fields were nullified with benzamil. Epithelization was more rapid in wounds with field strengths raised to 20, 40, and 60 mV/mm than in benzamil-treated wounds without field augmentation. Epithelization was most rapid at 40 mV/mm, the normal value. When fields were augmented to 80 and 100 mV/mm, the epithelization rate diminished significantly. We also augmented field strengths by increasing the Na+ concentration in the medium surrounding the digits. Wounds healed more slowly in 10 mM Na+ than in 1.5 mM Na+, the normal pond water concentration. When field strengths in 10 mM Na+ were diminished to levels found in contralateral digits at 1.5 mM Na+ by applying direct current, the epithelization rate was restored to normal. We conclude that newt wound epithelization rates are nearly maximal at normal wound field strengths. Field strengths significantly higher than normal (50% more) result in significantly diminished rates of epithelization.
有令人信服的证据表明，内源性电场对正常伤口上皮化是必需的，但尚不清楚增加正常场强是否能加速正常上皮化速率。尽管我们证实正常的侧向电场是正常美西螈上皮化速率所必需的，但通过直流电增加正常场强并不能显著提高上皮化程度。场强增加不到50%时，上皮化速率略有增加。当场强增加50%时，上皮化显著延迟。当我们对用苯扎米尔消除电场的伤口施加直流电时，也观察到了这种模式。场强提高到20、40和60 mV/mm的伤口比未增强电场的苯扎米尔处理伤口上皮化更快。在40 mV/mm（正常值）时上皮化最快。当场强增加到80和100 mV/mm时，上皮化速率显著降低。我们还通过增加手指周围培养基中的Na+浓度来增强场强。在10 mM Na+中伤口愈合比在正常池塘水浓度1.5 mM Na+中更慢。当通过施加直流电将10 mM Na+中的场强降低到对侧手指在1.5 mM Na+中发现的水平时，上皮化速率恢复正常。我们得出结论，蝾螈伤口上皮化速率在正常伤口场强下接近最大值。显著高于正常（多50%）的场强会导致上皮化速率显著降低。
