摘要目的 了解内皮素1和NO是否参与严重烧伤后早期心功能的迅即变化. 方法 (1)取31只Wistar大鼠,按随机数字表法分为假伤A组(7只)、烧伤A组(10只)、非选择性内皮素A/B受体拮抗剂PD142893组(7只)和选择性内皮素A受体拮抗剂BQ-123组(7只).后3组大鼠制成30%TBSA Ⅲ度烧伤模型,其中PD142893组和BQ-123组伤后即刻分别经静脉给予PD142893(0.1me,/kg)和BQ-123(30 nmol·kg~(-1)·min~(-1)).假伤A组除致假伤外,其余处理同烧伤A组.采用生理信号采集处理系统,监测假伤A组和烧伤A组大鼠伤前及伤后10、30、60、180 min时的左心室收缩压(LVSP)、心率、左心室压力最大上升/下降速率(LV±dp/dt max);计算4组大鼠伤后10 min上述各项心功能指标较各自伤前值变化的百分率.(2)另取20只Wistar大鼠,按随机数字表法分为假伤B组(4只)和烧伤B组(16只),同前致伤.烧伤B组分别于伤后10、30、60、180 min(每时相点4只)取心脏组织,假伤B组伤后即刻取心脏组织,用ELISA法检测内皮素1和NO含量. 结果 (1)与伤前值比较,烧伤A组大鼠伤后10 min LVSP、心率、LV+dp/dt max、LV-dp/dt max即明显下降(F值分别为7.14、16.40、14.09、14.98,P<0.05或P<0.01).假伤A组大鼠受伤前后4项心功能指标无明显变化(F值依次为0.59、0.51、1.03、1.04,P值均大于0.05).(2)与伤前值比较,伤后10 min烧伤A组LVSP下降27%、心率下降14%、LV+dp/dt max下降51%、LV-dp/dt max下降50%.PD142893组伤后10 min LVSP下降14%、心率升高4%、LV+dp/dt max下降31%、LV-dp/dt max下降14%,与烧伤A组相比各指标变化情况显著改善(F值分别为8.10、6.50、23.67、10.39,P<0.05或P<0.01).BQ-123组大鼠心率较伤前升高3%、LV-dp/dt max下降26%,与烧伤A组相比明显改善(F值分别为6.50、10.39,P<0.05或P<0.01);其LVSP和LV+dp/dt max变化百分率与烧伤A组接近(F值分别为8.10、23.67,P值均大于0.05).(3)与假伤B组相比,烧伤B组伤后10、60、180min心肌组织内皮素1含量均升高(F=2.85,P<0.05或P<0.01),NO含量于伤后60、180 min明显升高(F=1.87,P值均小于0.05). 结论 内皮素1可能参与了大鼠严重烧伤后早期心功能的迅即下降,在伤后立即出现的心肌损害中起重要作用.

abstractsObjective To explore whether endothelin-1 and NO are involved in the instant changes in cardiac function at early stage of severe bum. Methods (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 an-tagonist 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 in-jected with PD142893 (0.1 mg/kg) and BQ-123 (30 nmol·kg~(-1)·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 ± dp/dt max were monitored before injury and 10, 30, 60, 180 minutes post injury (PIM) using physiological signal aequisition and processing system. The respective changes in cardiac function indexes of rats 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. Results (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 respeetivly 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 <0.05 or P <0.01), and NO content increased significantly at PIM 60,180 (F=1.87, with P values all below 0.05). Conclusions 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.