Effect of high-voltage electrical stimulation and topical insulin on experimental cutaneous lesions

ABSTRACT This study aims to evaluate the effect of cathodic high voltage electrical stimulation (HVES), associated with topical insulin, on rat integumentary lesions. For this purpose, 42 Wistar rats (240±30 g) were submitted to surgical removal of 1 cm2 of dorsal skin and divided into six groups (n=7), treated for seven consecutive days: Control (C), placebo electrical stimulation (PES), cathodic electrical stimulation (ES), topical insulin (TI), placebo insulin (PI) and HVES associated with topical insulin (ES+I). HVES was administered 24 hours after surgery, 30 minutes per day, with a frequency of 100 Hz and a mean voltage of 60 V, maintained at the motor threshold. Lesion areas were recorded macroscopically on the first, fourth and eighth day, submitted to histological treatment for inclusion in paraplast® and staining in Hematoxylin and Eosin. Epithelialization and the numerical profile of the cells were obtained by histometric analysis. The Shapiro-Wilk and Anova one-way test was followed by the Bonferroni (p<0.05). There was a significant reduction in the area of the lesion by the eighth day of treatment, both in the ES and ES+I groups, when compared with other groups. Reepithelialization did not differ between groups, but the distance between the edges of the lesion was lower in the ES and ES+I groups. These same groups showed a significant increase (p<0.05) in the number of fibroblasts and a decrease in leukocytes. Thus, we can conclude that cathodic HVES accelerated the lesion repair process, with the topical application of insulin showing no additional effect.

摘要 本研究旨在评估阴极高压电刺激（cathodic high voltage electrical stimulation, HVES）联合局部胰岛素对大鼠皮肤损伤的修复效果。为此，选取42只体重为240±30 g的Wistar大鼠（Wistar rat），通过手术切除其背部1 cm²的皮肤组织，随后将其随机分为6组（每组n=7），连续7天接受对应处理：对照组（Control, C）、假电刺激组（placebo electrical stimulation, PES）、阴极电刺激组（cathodic electrical stimulation, ES）、局部胰岛素组（topical insulin, TI）、假胰岛素组（placebo insulin, PI）以及阴极高压电刺激联合局部胰岛素组（ES+I）。HVES于术后24小时开始施加，每日单次30分钟，参数设置为频率100 Hz、平均电压60 V，维持于运动阈值水平。分别于造模后第1、4、8天宏观记录损伤面积；将组织样本进行组织学处理，采用Paraplast®进行包埋，并施以苏木精-伊红（Hematoxylin and Eosin, HE）染色。通过组织计量学分析获取上皮化程度及细胞数量分布特征。统计分析采用Shapiro-Wilk检验及单因素方差分析（one-way ANOVA），后续以Bonferroni检验进行组间多重比较，检验水准设定为p<0.05。相较于其余各组，ES组与ES+I组在治疗第8天时的损伤面积均出现显著缩小。各组间再上皮化程度无显著差异，但ES组与ES+I组的损伤边缘间距显著降低。此外，上述两组的成纤维细胞数量显著升高（p<0.05），白细胞数量则显著降低。综上，阴极高压电刺激可加速皮肤损伤修复进程，而局部应用胰岛素未表现出额外的修复增效作用。