依那普利拉对严重烫伤大鼠早期心肌力学的影响

目的 了解依那普利拉对严重烫伤大鼠早期心肌力学的影响.方法 将84只SD大鼠背部造成30%TBSA的Ⅲ度烫伤后,随机分为烫伤组,伤后按Parkland公式腹腔注射等渗盐水;小剂量治疗组、中剂量治疗组、大剂量治疗组,伤后即刻分别腹腔注射1、2、4 mg/kg依那普利拉.烫伤组、小剂量治疗组伤后1、3、6、12、24 h,中剂量治疗组、大剂量治疗组伤后6、12 h左心室置管检测大鼠左心室收缩压(LVSP)、左心室舒张末期压(LVEDP)、左心室压力最大上升/下降速率(±dp/dt max),并处死大鼠取心肌组织检测血管紧张素Ⅱ(AⅡ)含量.另取6只大鼠作为假伤组,模拟烫伤后检测以上指标.结果 伤后3～24 h,烫伤组及各剂量治疗组大鼠LVSP、LVEDP、±dp/dt max值普遍低于假伤组(P＜0.05或P＜0.01);而各剂量治疗组LVSP、LVEDP、±dp/dt max值普遍高于烫伤组(P＜0.05或P＜0.01);伤后6、12 h,大剂量治疗组±dp/dt max明显低于小、中剂量治疗组.伤后1 h,烫伤组心肌组织AⅡ含量[(53.0±2.6)pg/200 mg]明显高于假伤组[(14.8±0.7)pg/200 mg,P＜0.01],6 h达高峰,以后逐渐下降,伤后24 h仍明显高于假伤组(P＜0.01);伤后3～24 h.小剂量治疗组AⅡ含量均明显高于假伤组(P＜0.05或P＜0.01),但均低于烫伤组.伤后6 h烫伤组AⅡ含量为(145.2±14.5)pg/200 mg,高于小、中、大剂量治疗组[(65.1±0.9)、(53.6±1.1)、(34.2±0.9)pg/200 mg,P ＜0.01].结论 严重烫伤后早期心肌组织损害明显.心功能即明显下降,依那普利托注射液可以改善心肌力学指标、保护心功能,以小剂量效果最为明显.

Protective effects of Enalaprilat on the myocardial kinetics in rats at early stage of severe scald

Objective To investigate the therapeutic effects of Enalaprilat on the myocardial kinetics in rats at early stage of severe scald. Methods Eighty-four SD rats were inflicted with 30% TBSA full-thickness scald,and randomly divided into scald(S,with intraperitoneal injection of isotonic saline according to Parkland formula,n=30),L(n=30),M(n=12)and H(n=12)groups.The rats in L,M,H groups were inIraperitoneally injected with 1,2,4 mg/kg Enalaprilat.Other 6 healthy rats were enrolled into study as control(C group).The myocardial kinetic parameters including left ventricular systolic pressure(LVSP),left ventricular end diastolic pressure(LVEDP),±dp/dt max and the levels of A Ⅱ in myoeardium were ob-served at 1,3,6,12 and 24 post scald hour(PBH)in L and S groups,and at 6,12 PBH in M and H groups.The above indices in C group were also examined. Results The Ievels of LVSP,LVEDP,±dp/dt max in C group were higher than those in other groups during 3～24 PBH(P＜0.05 or P＜0.01),while those in L,M,H groups were obviously higher than those in S group(P＜0.05 or P＜0.01).The level of±dp/dt max in H group at 6.12 PBH were obviously lower than those in L and M groups.The level of A Ⅱ in S group at 1 PBH was(53.0±2.6)pg/200 mg,which was significantly higher than thatin C group[(14.8±0.7)pg/200 mg,P＜0.05 or P＜0.01];it peaked at 6 PBH and lowered afterwards,and they were signif-icantly higher than that in C group at 24 PBH(P＜0.01).The levels of AⅡ in L group during 3～24 PBH were obviously higher than those in C group(P＜0.01),which were also lower than those in S group.The level of AⅡin S group was significantly higher than in L,M,H groups at 6 PBH[(145.2±14.5)pg/200 mg.vs.(65.1±0.9)pg/200 mg,(53.6±1.1)ps/200mg,(34.2±0.9)pg/200 mg,respectively,P＜0.01]. Conclusion Myocardium can be obviously damaged at early stage after severe scald.cardiac function is impaired.Enalaprilat injection(especially at low dose)can significantly ameliorate the myocardial kinetics indices,and it seems to exert a protective effect on cardiac function.