静脉注射表皮角朊细胞在烫伤大鼠各主要器官的分布

Distribution of dermal keratinocytes in different organs of scalded rats after intravenous injection

目的:烧伤创面的修复在很大程度上取决于表皮角朊细胞迁移、增殖和在相应器官的分化,通过静脉注射表皮角朊细胞,了解其在烫伤大鼠主要器官的分布情况。方法:实验于2003-03/2004-06在第三军医大学西南医院全军烧伤研究所完成。取38只Wistar新生鼠的表皮,采用Dispase和胰蛋白酶消化法,制备出角朊细胞悬液,然后用99Tcm标记。12只Wistar大鼠麻醉后沸水烫伤背部10s,制作20%Ⅲ度烫伤模型。实验分为对照组(假伤)、烫伤0d、烫伤3d和烫伤7d组,分别在假伤后1h内、烫伤后1h内、3d和7d经尾静脉注射99Tcm标记的角朊细胞悬液。注射后4h,单光子发射型计算机断层扫描仪检测大鼠主要器官(心、肝、脾、肺、肾、胸腺、皮肤或/和创面)的放射性活度,计算出各器官放射性计数角朊细胞分布的百分率。结果:4组12只大鼠进入结果分析。①对照组、烫伤0d组、烫伤3d组和烫伤7d组大鼠单光子发射型计算机断层扫描仪检测到的放射性活度主要分布在肺脏(66.8%～77.6%),肝脏10.8%～21.5%。②烫伤7d组大鼠肾脏的放射性活度百分率与对照组比较明显增加(12.2%,2.6%),皮肤或/和创面的放射性活度百分率在伤后仅略有增加(从0.64%到5.11%)。结论:经静脉注射的表皮角朊细胞主要随血循环向正常和烧伤大鼠的肺脏和肝脏迁移;烫伤后7d时角朊细胞向肾脏迁移显著增多,而向肺脏迁移有所减少。烫伤后迁移到皮肤或/和创面的角朊细胞仅略有所增多。

AIM:The plerosis of burn wound is mainly determined as the migration,proliferation and differentiation of dermal keratinocytes(KCs) in relevant organ.This study was aimed to investigate the distribution of main organ of scalded rats according to the intravenous injection of dermal KCs. METHODS:The experiment was completed at the Institute of Burn Research,Southwest Hospital,Third Military Medical University of Chinese PLA between March 2003 and June 2004.The epidermis of 38 newborn Wistar rats was selected to make KCs suspension with Dispase and trypsin digestion,and labeled by 99Tcm.Twenty percenwt of full thickness burns were made by 10 s exposure to boiling water on the dorsum of 12 anesthetized Wistar rats.All Wistar rats were divided into four groups:control group(sham injury),and three burned groups(0 day,3 days,7 days respectively) which the KCs suspension labeled by 99Tcm were injected within 1-hour sham injury,and 1-hour,3-day and 7-day scald respectively.After 4-hour injection,the whole body images of radioactivity were taken by single photon emission computed tomography(SPECT),including heart,liver,spleen,lungs,kidneys,thymus,normal skin and/or burn wound.The radioactivity of each organ was measured,and calculated as percentage of KCs distribution. RESULTS:Twelve rats in four groups entered final analysis.①Radioactivity measured with SPECT was located in lung(66.8%-77.6%) and liver(10.8%-21.5%) in control group and three burned groups(0 day,3 days,7 days respectively).②The radioactivity in 7-day burn group was 12.2%,which was obviously increasing as compared with that(2.6%) in control group.And the radioactivity of normal skin and/or burn wound was increased from 0.64%to 5.11%. CONCLUSION:After intravenous injection,the dermal KCs mainly immigrate in the lungs and liver of burned or non-burned rats along blood circle,and increasing immigration in the kidneys after 7-day burn,but decreasing immigration in the lungs.KCs immigrated into normal skin and/or burn wound is increasing after burn.