Influence of myocardial inhibition on injury to liver, kidney and intestine at early stage in rat with severe scald / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the influence of myocardial inhibition on injury to liver, kidney and intestine and blood perfusion at early stage in rat with severe burn.</p><p><b>METHODS</b>Thirty-two healthy male Wistar rats were enrolled in the study and randomly divided into sham scald, propranolol, scald control and scald + propranolol groups, with 8 rats in each group. After intraperitoneal injection of 10 g/L pentobarbital sodium for anesthesia, rats of the former two groups were sham scalded in a water bath of 37 degrees C for 18 s, while the latter two groups were inflicted with 30% TBSA full-thickness scald in a 97 degrees C water bath for 18 s. Rats were resuscitated with Ringer's lactate solution (4 mL x kg(-1) x 1% TBSA(-1), i. p.) following the Parkland formula 30 mins after the injury. At the same time, rats in propranolol and scald + propranolol groups received propranolol 0.75 mg/kg intravenously. After 6 hours, parameters of myocardiac mechanics (SBP, DBP, MAP, LVSP, LVEDP, +/- dp/dt max) were recorded by the multiple channel physiological signal collecting and processing system; blood flow of liver, kidney and intestine were detected with the laser doppler flowmetry; the serum contents of cTnI, TBA, beta2-MG and DAO were determined for reflecting injuries to the heart, liver, kidney and intestine, respectively.</p><p><b>RESULTS</b>Myocardiac mechanics parameters, with the exception of LVEDP, were decreased in propranolol group as compared with those in sham group (P <.05). All myocardiac mechanics parameters in burn control group were lower than those in sham group and higher than those in burn + propranolol group (P < 0.05). Blood flow of organs showed similar changes in above-mentioned 3 groups (P < 0.05). Organ damages as shown in burn control group [cTnI (4.86 +/- 0.29) microg/L, TBA (83.6 +/- 18.2) micromol/L, beta2-MG (2.75 +/- 0.19) mg/L, DAO (1.45 +/- 0.09) x 10(3) U/L] were more serious than those in sham control group [cTnI (1.73 +/- 0.09) microg/L, TBA (24.5 +/- 2.4) micromol/L, beta2-MG (1.15 +/- 0.18) mg/L, DAO (0.87 +/- 0.13) x 10(3) U/L], and less serious than those in scald + propranolol group [cTnI 5.95 +/- 0.42 microg/L, TBA 125.8 +/- 21.3 micromol/L, beta2-MG 3.25 +/- 0.17 mg/L, DAO (1.83 +/- 0.13) x 10(3) U/L] (P < 0.05).</p><p><b>CONCLUSIONS</b>Propranolol can aggravate injury to the liver, kidney and intestine at early stage in rat with severe burn, suggesting that "shock heart" may be one of initial factors in lowering blood flow to the organs, thus inducing injury to them.</p>

Effects of angiotensin (1-7) and enalaprilat on function of isolated rat heart perfused by burn serum / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate effects of angiotensin (1-7) [Ang (1-7)] and enalaprilat on function of isolated rat heart perfused by burn serum.</p><p><b>METHODS</b>Eighty SD rats were used to prepare burn serum. Hearts of another 24 SD rats were isolated to reproduce Langendorff perfusion model. The rat hearts were divided into different groups with different perfusion fluids as K-H buffer group, K-H buffer containing 20% burn serum group (burn serum group), K-H buffer containing 20% burn serum and 2 microg/mL enalaprilat group (enalaprilat group), and K-H buffer containing 20% burn serum and 1 nmol/mL Ang (1-7) group [Ang(1-7) group]. The rat hearts were perfused for 30 mins with each of above-mentioned fluids in different groups. Then left ventricular systolic pressure (LVSP), left ventricular end diastolic pressure (LVEDP), +/- dp/dt max, coronary flow(CF), level of creatine kinase (CK) and lactate dehydrogenase (LDH) in respective coronary effluent were determined.</p><p><b>RESULTS</b>Compared with LVSP (11.2 +/- 1.0 kPa, 1 kPa = 7.5 mm Hg), +dp/dt max (642 +/- 53 kPa/s), -dp/dt max (380 +/- 61 kPa/s) and CF level in K-H buffer group, CF, LVSP (5.9 +/- 0.8, 8.0 +/- 1.1, 8.9 +/- 1.3 kPa, respectively), +dp/dt max (275 +/- 37, 454 +/- 48, 479 +/- 63 kPa/s, respectively), -dp/dt max (135 +/- 35, 219 +/- 47, 277 +/- 58 kPa/s, respectively) of burn serum group, those levels in Ang (1-7) group, and enalaprilat group were decreased obviously (P < 0.05 or P < 0.01), but LVEDP, level of CK and LDH in coronary effluent were increased. Compared with those parameters in burn serum group, CF, LVSP, +/- dp/dt max of Ang (1-7) group and enalaprilat group were increased obviously (P < 0.05 or P < 0.01), and LVEDP, level of CK and LDH in coronary effluent were decreased obviously (P < 0.01).</p><p><b>CONCLUSIONS</b>Ang (1-7) and enalaprilat can effectively improve left ventricular function of isolated rat heart perfused by burn serum and mitigate myocardial injury.</p>

Instigating effect of shock heart on the injury to the liver, kidney and intestine at early stage of severe burn in rat / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the instigating effect of "shock heart" on injury to liver, kidney and intestine at early stage of severe burn in rat.</p><p><b>METHODS</b>Fifty-six healthy male Wistar rats were enrolled in the study and randomly divided into normal control (n=8, without treatment, NC) and burn (n=48, inflicted with 30% TBSA full-thickness scald, B) groups. The rats in B group were intraperitoneally injected with Ringer's lactate solution (4 ml x kg(-1) x 1% TBSA(-1) 30 minutes after burn following the Parkland formula, and they were observed at 0.5, 1.0, 3.0, 6.0, 12.0, 24.0 post-burn hour (PBH), with 8 rats at each time point. The parameters concerning myocardial mechanics, including systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), left ventricular systolic pressure (LVSP), left ventricular end diastolic pressure( LVEDP), +/-dp/dt max were recorded. The volume of blood flow in liver, kidney and intestine were detected. The serum contents of cTnI, TBA, 32-MG, DAO were determined.</p><p><b>RESULTS</b>In B group, LVSP and +/- dp/dt max decreased at 1.0 PBH, SBP, DBP and MAP decreased at 3.0 PBH ,all parameters of myocardial mechanics, decreased at 6.0 PBH and still lower than those in NC group at 24.0 PBH (P < 0.01). The volume of blood flow in liver, kidney and intestine in B group were markedly decreased at 1.0 PBH, and gradually decreased during 1.0-12.0 PBH, which were still lower than those in NC group at 24.0 PBH (P < 0.05 or P < 0.01). Compared with that in NC group (1.71 +/- 0.07 microg/L), the serum content of cTnI in B group were increased at 0.5 PBH (2.22 +/- 0.08 microg/ L, P < 0.01), and peaked at 12.0 PBH (7.07 +/- 0.44 microg/L), and persisted at high level (4.57 +/- 0.30 microg/L) at 24.0 PBH. The serum contents of TBA at 3.0 PBH, beta2-MG at 1.0 PBH, DAO at 1.0 PBH was obviously higher than those in NC group (P < 0.05 or P < 0.01), which all showed ascending tendency during 1.0-12.0 PBH.</p><p><b>CONCLUSION</b>Myocardial damage is earlier than other organs after severe burn, which is significantly correlated with the parameters of other organs damage and their blood flow volume. Shock heart may be one initiate factor to induce the damage of liver, kidney and intestine and decrease of their blood flow volume after severe burn.</p>

Effects of single or combined administration of cedilanid and enalaprilat on visceral damages in early stage of severe scald in rats / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the effects of single or combined administration of cedilanid and small-dose of enalaprilat on heart, liver, kidney and intestine damages at early stage of severe scald in rats.</p><p><b>METHODS</b>Forty healthy male Wistar rats were enrolled in the study and randomly divided into: sham, burn control, cedilanid, enalaprilat, cedilanid + enalaprilat groups, with 8 rats in each group. Rats, except that of sham group (simulated scald with 37 degrees C water) were inflicted with 30% TBSA full-thickness scald, and were injected with Ringer's lactate solution (4 mLxkg(-1)x1% TBSA(-1)) intraperitoneally 30 minutes after burn. Then rats in cedilanid group were given cedilanid injection (0.2 mg/kg) intravenously, and those in enalaprilat group were given enalaprilat (1 mg/kg), and cedilanid + enalaprilat group with cedilanid and enalapril in the same dosage. At 6 post burn hour (PBH) or sham injury, parameters of myocardiac mechanics were recorded with the Multiple Channel Physiological Signal Collecting and Processing System. The blood flow of the liver, kidney and intestine was respectively detected with the Laser Doppler Flowmetry at 6 PBH. Serum contents of cTnI, TBA, beta2-MG and DAO were determined at 6 PBH to reflect visceral damages.</p><p><b>RESULTS</b>Compared with those in sham group, the parameters of myocardiac mechanics and blood flow of liver, kidney, intestine (158 +/- 32, 156 +/- 46, 119 +/- 30 PU, respectively) in burn control group were obviously decreased (P < 0.05), and the serum contents of cTnI, TBA, beta2-MG, DAO (5.0 +/- 0.3 microg/L, 82 +/- 23 micromol/L, 2.55 +/- 0.15 mg/L, 1.52 +/- 0.08 kU/L, respectively) in burn control group were obviously increased (P < 0.05). Compared with those in burn control group, the parameters of myocardiac mechanics and blood flow of liver, kidney, intestine in the cedilanid or enalaprilat groups increased markedly, and their serum contents of cTnI, TBA, beta2-MG, DAO decreased significantly (P < 0.05). Compared with those in burn control group, the parameters of myocardiac mechanics and blood flow of liver, kidney, intestine (240 +/- 49, 239 +/- 75, 194 +/- 55 PU, respectively) in cedilanid + enalaprilat group increased significantly (P < 0.05), and the serum contents of cTnI, TBA, beta2-MG, DAO (3.43 +/- 0.21 microg/L, 47 +/- 8 micromol/L, 2.01 +/- 0.16 mg/L, 1.17 +/- 0.15 kU/L, respectively) were decreased (P < 0.05).</p><p><b>CONCLUSION</b>Single administration of cedilanid or small-dose enalaprilat can ameliorate impairment of cardiac functions, prevent damages to liver, kidney and intestine in early stage of severe scald in rats. Combined administration of cedilanid and small-dose enalaprilat seems to be more effective.</p>

Protective effects of administration of enalapril maleate on rat myocardial damage in early stage of burns / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the preventive and therapeutic effects of enalapril maleate (Enalaprilat) (E) on myocardial damage in early stage after burns.</p><p><b>METHODS</b>A total of 60 SD rats were subjected to 30% TBSA III degree scald injury, and randomly divided into scald group (with conventional fluid transfusion after scald) and ENA group (with intraperitoneal injection of 1 mg/kg Enalaprilat after scald). Normal control consisted of 6 rats. Plasma levels of cTnI and CK-MB were determined in all the groups at 1, 3, 6, 12, 24 post-scald hours (PSH) by enzyme linked immunosorbent assay. The pathological changes in myocardium were observed at the same time-points.</p><p><b>RESULTS</b>(1) The serum level of cTnI and CK-MB in scald group were significantly higher than that of normal controls at each time-point (P < 0.01). The serum level of cTnI and CK-MB in ENA group were (1.32 +/- 0.12 microg/L to 2.47 +/- 0.22 microg/L) and (438 +/- 68 U/L to 5569 +/- 322 U/L), respectively, which were obviously lower than those in B group (6.42 +/- 0.96 microg/L to 15.10 +/- 3.69 microg/L) and (2556 +/- 74 U/L to 8047 +/- 574 U/L, P < 0.05 or P < 0.01) at different time-points. (2) Compared with normal controls, cloudy swelling, stromal blood vessel dilatation and congestion inflammatory cell infiltration were observed in scald group, but these pathological changes were less marked in ENA group.</p><p><b>CONCLUSION</b>Severe myocardial damage in rat occurred early after burns. Enalaprilat injection can markedly alleviate myocardial damage.</p>