ABSTRACT
Objective@#To investigate the significance of intestinal fatty acid binding protein (IFABP) in the evaluation of intestinal barrier dysfunction of mice at the early stage of severe burn injury.@*Methods@#Thirty-six 8-week-old C57BL/6 male mice were collected and divided into normal control group (n=6) and scald group (n=30) according to random number table. Back of each mouse in scald group was placed into hot water of 90 ℃ for 10 s, causing full-thickness scald (hereinafter refer to as burn) of 30% total body surface area, while mice in normal control group were not inflicted with burns. Six mice in normal control group were taken, and 6 mice in scald group at 1, 2, 6, 12, and 24 h post injury were taken respectively. The portal vein blood of each mouse was extracted and the plasma was separated to measure intestinal permeability with fluorescin isothiocyanate-dextran fluorescence probe tracing method and plasma IFABP content by enzyme-linked immunosorbent assay. The distal ileum tissue of mice in normal control group and scald group at each time point post injury was collected to observe the morphology of the intestinal mucosa tissue by hematoxylin-eosin staining. Data were processed with one-way analysis of variance and Student-Newman-Keuls test, and pearson correlation test was used to analyze the correlation between intestinal permeability and plasma IFABP content of burned mice.@*Results@#(1) At 1, 2, 6, 12, and 24 h post injury, the intestinal permeability of mice in scald group was 2.7±0.8, 5.4±2.5, 7.3±4.2, 12.4±6.1, 1.4±0.7, respectively, obviously higher than 1.0±0.4 of normal control group (P<0.05 or P<0.01). The intestinal permeability of mice in scald group showed an increasing trend post injury, reaching the peak at 12 h post injury, and rapidly falling back at 24 h post injury. (2) At 1, 2, 6, 12, and 24 h post injury, the plasma IFABP content of mice in scald group was (64±11), (59±12), (76±18), (111±22), and (66±10) ng/mL, obviously higher than (35±8) ng/mL in normal control group (P<0.05 or P<0.01). The plasma IFABP content of mice in scald group showed an increasing trend post injury, reaching the peak at 12 h post injury, and rapidly decreasing at 24 h post injury. (3) Uniform thickness of mucosa, intact epithelia, regularly arranged villi, and no inflammatory cell infiltration were observed in ileum of mice in normal control group. In ileum of mice in scald group, shortened villi of mucosa with different degrees, edema of lamina propria, and infiltration of neutrophils were observed at 1 and 2 h post injury; obviously damaged and partially exfoliated ileal mucosa, disorderly arranged and broken villi, degenerated and necrotic epithelial cells, dilated central lacteal, and infiltration of lymphocytes and neutrophils were observed at 6 and 12 h post injury; the damage of ileal mucosa was alleviated, and basically intact epithelia, dilated central lacteal, and infiltration of inflammatory cells were observed at 24 h post injury. (4) There was a significantly positive correlation between the intestinal permeability and the plasma IFABP content of burned mice (r=0.841, P<0.05).@*Conclusions@#The plasma IFABP can be used as a good biological indicator for the evaluation of intestinal barrier dysfunction of mice at the early stage of severe burn injury.
ABSTRACT
Objective@#To explore the effects of different doses of dopamine on organ function of rats at early stage of severe scald.@*Methods@#Thirty-two male Wistar rats aged 8 to 12 weeks were divided into sham injury (SI) group, simple resuscitation (SR) group, small dose (SD) group, and moderate dose (MD) group according to the random number table, with 8 rats in each group. After rats in the 4 groups were performed cardiac catheterization, rats in group SI were sham injured on the back by immersing in 37 ℃ warm water for 18 s, and rats in the other 3 groups were inflicted with 30% total body surface area (TBSA) full-thickness scald on the back by immersing in 97 ℃ hot water for 18 s. Rats in group SI were not treated after the injury, while rats in the other 3 groups were performed fluid resuscitation for 24 h through jugular vein catheter with micro syringe pump according to the Parkland formula. They were given 4.0 mL·kg-1·% TBSA-1 normal saline during the first 24 h, of which they were given half of the total amount for the first 8 h, and they were given half of the total amount for the second and third 8 h. Rats in group SR were infused normal saline only, while rats in group SD and group MD were infused normal saline+ 1.25 μg·kg-1·min-1dopamine and normal saline+ 6.00 μg·kg-1·min-1 dopamine respectively. Volume of 0.5 mL venous blood of all rats were taken through the cardiac catheter with serum separated at post injury hour (PIH) 1, 3, 6, 12, and 24. Serum content of cardiac troponin I (cTnI) was determined by enzyme-linked immunosorbent assay; serum content of diamine oxidase (DAO) was detected by ultraviolet spectrophotometer; serum content of β2-microglobulin (β2-MG) was determined by latex-enhanced immunoturbidimetric assay; serum content of total bile acid (TBA) was determined by enzyme colorimetry; serum content of lactic acid, malondialdehyde, and myeloperoxidase (MPO) was determined by ultraviolet spectrophotometer. Data were processed with analysis of variance for repeated measurement, one-way analysis of variance, least significant difference test, and Bonferroni correction.@*Results@#(1) At PIH 1, 3, 6, 12, and 24, serum content of cTnI of rats in group SR, group SD, and group MD [(2.69±0.19), (3.04±0.19), (4.96±0.25), (6.88±0.28), (4.75±0.31) μg/L, (2.70±0.14), (3.08±0.13), (5.06±0.19), (7.11±0.21), (4.89±0.16) μg/L, (2.18±0.14), (2.54±0.09), (3.97±0.14), (5.46±0.34), (3.32±0.33) μg/L] were higher than that in group SI [(1.70±0.08), (1.70±0.08), (1.69±0.11), (1.69±0.08), (1.70±0.08) μg/L, P<0.05], serum content of cTnI of rats in group SR and group SD was similar (P>0.05), and serum content of cTnI of rats in group MD was lower than that in group SR and group SD (P<0.05). (2) At PIH 1 to 24, serum content of DAO of rats in group SR, group SD, and group MD was higher than that in group SI (P<0.05), serum content of DAO of rats in group SR and group MD was similar (P>0.05), and serum content of DAO of rats in group SD was lower than that in group SR and group MD (P<0.05). (3) At PIH 1 to 24, serum content of β2-MG of rats in group SR, group SD, and group MD was higher than that in group SI (P<0.05), serum content of β2-MG of rats in group SR and group MD was similar (P>0.05), and serum content of β2-MG of rats in group SD was lower than that in group SR and group MD (P<0.05). (4) At PIH 1 to 24, serum content of TBA of rats in group SR, group SD, and group MD was similar (P>0.05) and higher than that in group SI (P<0.05). (5) At PIH 1 to 24, serum content of lactic acid of rats in group SR, group SD, and group MD was higher than that in group SI (P<0.05), serum content of lactic acid of rats in group SR and group MD was similar (P>0.05), and serum content of lactic acid of rats in group SD was lower than that in group SR and group MD (P<0.05). (6) At PIH 1 to 24, serum content of malondialdehyde and MPO of rats in group SR, group SD, and group MD was higher than that in group SI (P<0.05), serum content of malondialdehyde and MPO of rats in group SR and group MD was similar (P>0.05), and serum content of malondialdehyde and MPO of rats in group SD was significantly lower than that in group SR and group MD (P<0.05).@*Conclusions@#With effective liquid recovery, dopamine of MD can improve early cardiac function of rats with severe scald, while dopamine of SD can alleviate tissue ischemia and hypoxia, reduce oxygen free radical damage in internal organs, and improve functions of intestine and kidney.