Li Bai-xing, Huang Yue-sheng, Yin Ze-gang
Institute of Burn Research, Southwest Hospital, State Key Laboratory of Trauma, Burns and Combined Injury, the Third Military Medical University, Chongqing 400038, China.
Zhonghua Shao Shang Za Zhi. 2010 Feb;26(1):14-7.
To explore whether endothelin-1 and NO are involved in the instant changes in cardiac function at early stage of severe burn.
(1) Thirty-one Wistar rats were divided into sham burn A group (SA, n = 7), burn A group (BA, n = 10), non-selective endothelin A/B receptor antagonist PD142893 group (n = 7), and the selective endothelin A receptor antagonist BQ-123 group (n = 7) according to the random number table. Rats in the latter three groups were inflicted with 30% TBSA full-thickness burn. Immediately after injury, rats in PD142893 group and BQ-123 group were intravenously injected with PD142893 (0.1 mg/kg) and BQ-123 (30 nmol x kg(-1) x min(-1)) respectively. Rats in SA group were treated the same as rats in BA group except for sham injury. The cardiac function indexes of rats in BA and SA groups including left ventricular systolic pressure (LVSP) heart rate (HR) and LV + or - dp/dt max were monitored before injury and 10, 30, 60, 180 minutes post injury (PIM) using physiological signal acquisition and processing system. The respective changes in cardiac function indexes of rate in each group between PIM 10 and pre-injury in the value of percentage were calculated. (2) Another 20 Wistar rats were enrolled and divided into sham burn B group (SB, n = 4) and burn B group (BB, n = 16) according to the random number table, and they were subjected to above-mentioned injury. Heart tissues of rats in BB group were obtained at PIM 10, 30, 60, and 180 respectively (4 rats at each time point), and that in SB group were obtained immediately after injury. Endothelin-1 and NO contents in heart tissues were determined with ELISA.
(1) Compared with the pre-injury value, LVSP, HR, LV +dp/dt max, LV -dp/dt max of rats in BA group decreased significantly since PIM 10 (with F value respectively 7.14, 16.40, 14.09 14.98, P < 0.05 or P < 0.01). No significant change was observed in above 4 indexes in rats of SB group between above mentioned two time points (with F value respectively 0.59, 0.51, 1.03, 1.04, P values all above 0.05). (2) In BA group, compared with the pre-injury value, LVSP decreased 27%, HR decreased 14%, LV +dp/dt max decreased 51%, LV -dp/dt max decreased 50% at PIM 10. Compared with those in BA group at PIM 10, cardiac function indexes were improved significantly in PD142893 group, with LVSP decreased 14% (F = 8.10, P < 0.01), HR increased 4% (F = 6.50, P < 0.01), LV +dp/dt max decreased 31% (F = 23.67, P < 0.05), LV -dp/dt max decreased 14% (F = 10.39, P < 0.01). In BQ-123 group, compared with the pre-injury value, HR increased 3%, LV -dp/dt max decreased 26% at PIM 10, which were obviously improved as compared with those in BA group (with F value respectively 6.50 and 10.39, P < 0.05 or P < 0.01); the percentage changes of LVSP and LV +dp/dt max in BQ-123 group were close to that in BA group (with F value respectively 8.10 and 23.67, P values both above 0.05). (3) Compared with those in SB group, myocardial tissue endothelin-1 content of rats in BB group increased significantly at PIM 10, 60, 180 (F = 2.85, P < 00.05 or P < 0.01), and NO content increased significantly at PIM 60, 180 (F = 1.87, with P values all below 0.05).
Endothelin-1 may participate in the instant decline of cardiac function of rats at early stage of severe burn, and plays an important role in the instant myocardial damage after injury.
探讨内皮素-1和一氧化氮是否参与严重烧伤早期心脏功能的即刻变化。
（1）将31只Wistar大鼠按随机数字表法分为假烧伤A组（SA，n = 7）、烧伤A组（BA，n = 10）、非选择性内皮素A/B受体拮抗剂PD142893组（n = 7）和选择性内皮素A受体拮抗剂BQ-123组（n = 7）。后三组大鼠均造成30%体表面积的全层烧伤。伤后即刻，PD142893组和BQ-123组大鼠分别静脉注射PD142893（0.1 mg/kg）和BQ-123（30 nmol·kg⁻¹·min⁻¹）。SA组除假伤外，处理同BA组。采用生理信号采集处理系统监测BA组和SA组大鼠伤前及伤后10、30、60、180分钟（PIM）的心脏功能指标，包括左心室收缩压（LVSP）、心率（HR）及LV +或 - dp/dt max。计算每组大鼠PIM 10时与伤前心脏功能指标变化值的百分比。（2）另取20只Wistar大鼠，按随机数字表法分为假烧伤B组（SB，n = 4）和烧伤B组（BB，n = 16），进行上述致伤处理。分别于PIM 10、30、60、180分钟（每个时间点4只大鼠）取BB组大鼠心脏组织，伤后即刻取SB组大鼠心脏组织。用ELISA法测定心脏组织中内皮素-1和一氧化氮含量。
（1）与伤前值比较，BA组大鼠自PIM 10起LVSP、HR、LV +dp/dt max、LV -dp/dt max均显著降低（F值分别为7.14、16.40、14.09、14.98，P < 0.05或P < 0.01）。SB组大鼠上述4项指标在上述两个时间点间无明显变化（F值分别为0.59、0.51、1.03、1.04，P值均> 0.05）。（2）在BA组，PIM 10时与伤前值比较，LVSP降低27%，HR降低14%，LV +dp/dt max降低51%，LV -dp/dt max降低50%。与BA组PIM 10时比较，PD142893组心脏功能指标明显改善，LVSP降低14%（F = 8.10，P < 0.01），HR升高4%（F = 6.50，P < 0.01），LV +dp/dt max降低31%（F = 23.67，P < 0.05），LV -dp/dt max降低14%（F = 10.39，P < 0.01）。在BQ-123组，PIM 10时与伤前值比较，HR升高3%，LV -dp/dt max降低26%，与BA组比较明显改善（F值分别为6.50和10.39，P < 0.05或P < 0.01）；BQ-123组LVSP和LV +dp/dt max的变化百分比与BA组接近（F值分别为8.10和23.67，P值均> 0.05）。（3）与SB组比较，BB组大鼠心肌组织内皮素-1含量在PIM 10、60、180分钟时显著升高（F = 2.85，P < 0.05或P < 0.01），一氧化氮含量在PIM 60、180分钟时显著升高（F = 1.87，P值均< 0.05）。
内皮素-1可能参与严重烧伤早期大鼠心脏功能的即刻下降，并在伤后即刻心肌损伤中起重要作用。
