摘要
目的探讨糖尿病脓毒症大鼠肺微血管内皮细胞损伤及一氧化氮系统在其发生机制中的作用。方法中国医科大学动物实验中心，清洁级Wistar大鼠64只随机（随机数字法）分为A、B、C、D四组，（健康对照组，n=16、糖尿病组，n=16、单纯脓毒症组，n=16、糖尿病发生脓毒症组，n=16）。糖尿病模型，一次性腹腔注射链脲左菌素60mg／kg，48h后随机测定尾静脉末梢血糖≥16．67mmol／L，为模型成功，饲养4周后下一步试验。脓毒症模型：一次性尾静脉注射大肠杆菌内毒素10mg／kg体质量。测定全血Tie-2mRNA表达，测定肺脏组织对伊文思蓝渗透性及肺脏干湿质量比、血清及肺组织NO含量，real-timePCR测定肺组织诱生型一氧化氮合酶（inducible nitric oxide synthase, iNOS）、内皮型一氧化氮合酶（endothelial nitric oxide synthase，eNOS）、DDAH2mRNA水平。数据采用单因素方差分析，并用LSD法进行组问两两比较，P〈0．05为差异有统计学意义。结果糖尿病脓毒症组较单纯脓毒症组全血Tie-2mRNA表达增多（19．72±0．70）VS．（3．99±0．92），P=0．00，肺干湿质量比更为降低（0．19±0．01）VS．（0．22±0．01），P=0．000，肺脏对EBD通透性增加更为严重（3．76±0．77）vs．（1．74±0．24），P=0．000，血清一氧化氮水平增高水平D组低于C组，（123．13±4．24）VS．（188．30±5．18），P=0．000。在肺组织中表达，两组均显示出高NO水平（53．62±6．70），（23．63±3．92）vs．（10．37±1．29），P=0．00，且D组近2倍高于C组（P=0．00）A、B、C组eNOS表达各组之间差异无统计学意义，D组低于A组，（0．07±0．02）VS．（0．38±0．05），P=0．017；iNOS表达C、D组均高于A组，（80．23±2．49），（32．48±5．37）VS．（1．74±0．23），均P=0．00；D组高于C组（P=0．00）。DDAH2mRNA水平D及C组均低于A组，（0．49±0．13），（7．26±0．50）VS．（11．96±0．550，P均=0．00；D组低于C组（P=0．00）。结论糖尿病脓毒症机体表现为更为严重内皮细胞损伤，严重NO系统调节失衡是糖尿病脓毒症血管内皮损伤加重的可能机制。
Objective To investigate the pulmonary microvascular responsiveness of diabetic animals to sepsis and the potential mechanism of NO system. Methods Sixty-four Wistar rats of clean grade were randomly （random number） divided into 4 groups, namely normal control group （group A, n = 16）, diabetes group （group B, n = 16）, sepsis group （group C, n = 16）, diabetes and sepsis group （group D, n = 16）. Diabetic mellitus model was made in rats with injection of streptozotocin , STZ （65 mg/kg）.Successful model was defined as the blood glucose value≥16. 67 mmol/L 48 hours after injection of STZ. All animals were fed 4 weeks before initiation of next experiment. The sepsis model was established by intravenous injection of LPS （ 10 mg/kg） in rats. RT-PCR was used to determine the mRNA expression of Tie-2 in rats＇blood. The ratio of dry/wet of lung tissue and the extravasation of Evans blue dye into the lung were detected. Quantitation of NO in lung tissue and serum was measured by using Griess method. RT-PCR was also used for determination of iNOS, eNOS, DDAH2 mRNA expressions in lung tissue. Data were analyzed with ANONA and LSD method for comparison between groups, and P 〈 0. 05 was considered statistically significant. Results Compared with septic group, the diabetic rats with sepsis group demonstrated higher expression of Tie-2 mRNA in blood （ 19. 72 ± 0. 70） vs. （3.99 ± 0. 92）, P = 0. 00, lower ratio of d,：c/wet in lung tissue （0. 19 ~0.01 ） vs. （0. 22 ±0. 01 ）, P =0. 000, higher permeability of Evans blue dye into lung tissue （ 3.76 ± 0. 77 ） vs. （ 1.74 ± 0. 24）, P = 0. 000. Serum NO level was lower in group D than that in group C （123.13 ±4. 24） vs. （188.30 ±5.18） , P =0. 000, however, NO levels in lung tissue of both group D and group C were higher than that in control group （53.62 ± 6. 70）, （23.63 ± 3.92） vs. （ 10. 37 ± 1.29）, P =0. 00, and NO level in group D was higher in 2 times than that in group C （P = 0. 00）. However, there were no differences in eNOS expression among groups A, B and C, but the difFErence in eNOS expression was present between group D with lower expression and group A, that lower in group D （0. 07 ±0. 02） vs. （0. 38 -0. 05） , P =0. 017. Compared with group C, the expression of iNOS was higher in group D （80.23 ±2.49） , （32.48 ±5.37） vs. （1.74 ±0.23）, P=0. 00）, and the expression of DDAH2 was lower in group D （0.49 ±0.13）, （7.26 ±0.50） vs. （11.96 ±0.55）. Conclusions Diabetic rats with sepsis enhanced endothelial cell damages . Diabetes deteriorates the regulatory activity of NO system, suggesting the potential mechanism of the worsened damages of EC in diabetic sepsis host.
出处
《中华急诊医学杂志》
CAS
CSCD
北大核心
2013年第10期1105-1111,共7页
Chinese Journal of Emergency Medicine
基金
高等学校博士学科点专项科研基金联合资助课题（20102104110003）
