Lv Gen-Fa, Hou Hong-Yi, Chen Bi, Zhang Wan-Fu, Zhu Xiong-Xiang, Dong Mao-Long, Hu Da-Hai
Center of Burn Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an 710032, Shanxi, China.
Zhongguo Wei Zhong Bing Ji Jiu Yi Xue. 2008 Dec;20(12):724-6.
To study the protective effect of intensive insulin treatment on cardiac myocytes of severely scalded rats.
Eighteen model Sprague-Dawley (SD) rats were subjected to 30% total body surface area (TBSA) full thickness injury, and they were divided into three groups with 6 rats in each group. The right jugular vein was cannulated for fluid resuscitation and administration of drugs. The rats in burn group were injected with normal saline, the intensive insulin group with injection of insulin to maintain plasma glucose content in normal range, and the sham burn group received physiologic dose of saline without burn injury. Plasma glucose was monitored after burn injury. Rats were sacrificed at 6 hours postburn to examine plasma myocardial enzymes spectrum as well as histological and ultrastructure changes in cardiac tissue. The expression of p-Akt was detected by western blotting.
Plasma glucose level was significantly elevated in burn group within postburn 6 hours as compared with the sham burn group, and lowered in intensive insulin group (4.5 approximately 5.2 mmol/L vs. 7.6 approximately 8.4 mmol/L, P<0.05 or P<0.01). And the intensive insulin therapy could effectively inhibit the release of cardiac enzymes [lactate dehydrogenase (LDH): (2 369.3+/- 178.9) U/L vs. (2 684.1+/-335.0) U/L, P<0.05; alpha-hydroxybutyrate dehydrogenase (alpha-HBD): (576.7+/-219.2) U/L vs. (1 002.0+/-347.1) U/L, P<0.01; creatine kinase (CK): (1 041.9+/-623.2) U/L vs. (2 447.1+/-1 183.7) U/L, P<0.01]. The expression of p-Akt was significantly strengthened in the intensive insulin group (1.18+/-0.43 vs. 0.24+/-0.11, P<0.01). Light microscopic and electron microscopic examinations showed that intensive insulin therapy could alleviate the injury to myocardial cells and structural changes.
Intensive insulin treatment possesses protective effect on cardiomyocytes after a severe burn, and it is related to its up-regulation of phosphorylation level of Akt in cardiomyocyte, thus inhibiting the damage to myocytes.
研究强化胰岛素治疗对严重烫伤大鼠心肌细胞的保护作用。
18只Sprague-Dawley（SD）模型大鼠行30%总体表面积（TBSA）全层损伤，分为3组，每组6只。经右颈静脉插管用于液体复苏和给药。烧伤组大鼠注射生理盐水，强化胰岛素组注射胰岛素以维持血浆葡萄糖含量在正常范围，假烧伤组给予生理剂量生理盐水但无烧伤损伤。烧伤后监测血浆葡萄糖。烧伤后6小时处死大鼠，检测血浆心肌酶谱以及心脏组织的组织学和超微结构变化。采用蛋白质印迹法检测p-Akt的表达。
与假烧伤组相比，烧伤组烧伤后6小时内血浆葡萄糖水平显著升高，而强化胰岛素组降低（4.5～5.2 mmol/L对7.6～8.4 mmol/L，P<0.05或P<0.01）。强化胰岛素治疗可有效抑制心肌酶的释放[乳酸脱氢酶（LDH）：（2 369.3±178.9）U/L对（2 684.1±335.0）U/L，P<0.05；α-羟丁酸脱氢酶（α-HBD）：（576.7±219.2）U/L对（1 002.0±347.1）U/L，P<0.01；肌酸激酶（CK）：（1 041.9±623.2）U/L对（2 447.1±1 183.7）U/L，P<0.01]。强化胰岛素组p-Akt的表达显著增强（1.18±0.43对0.24±0.11，P<0.01）。光镜和电镜检查显示，强化胰岛素治疗可减轻心肌细胞损伤和结构改变。
强化胰岛素治疗对严重烧伤后的心肌细胞具有保护作用，这与其上调心肌细胞中Akt的磷酸化水平从而抑制心肌细胞损伤有关。
