The Role of Hydrogen Sulfide in Acute Liver Injury Induced by Traumatic Stress in Rats / 法医学杂志

OBJECTIVE@#To explore the role of hydrogen sulfide (H2S) in acute liver injury induced by crushing hind limbs of rats.@*METHODS@#The rats were randomly divided into the following groups: control, crushing, H2S donor sodium hydrosulfide (NaHS) + crushing, H2S inhibitor propargylglycine (PAG) + crushing group. The acute liver injury model was established by 'crushing the hind limbs of rats with standard weight. Rats were sacrificed at 30 min and 120 min after the crush. The activities of serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were measured by colorimetric method, and the content of H2S in plasma and the contents of malondialdehyde (MDA), protein carbonyl, glutathione (GSH) in the liver and the activity of H2S generating enzyme (cystathionine y-lyase, CSE) were determined by chemical method. The expression of CSE mRNA in liver was detected by RT-PCR.@*RESULTS@#For crush injury group, the levels of AST and ALT in serum, MDA and protein carbonyl in liver increased. The levels of GSH, CSE, CSE mRNA in liver and H2S in serum decreased. The administration of NaHS before limbs crush could attenuate the changes of liver injury, but the pre-treatment with PAG could exacerbate the changes.@*CONCLUSION@#The decrease of H2S production could involve in mediating the acute liver injury induced by traumatic stress in rats.

Effects of restraint position on changes of diaphragmatic mechanical characteristic in rats / 法医学杂志

OBJECTIVE@#To observe effects of restraint position on the changes of diaphragmatic mechanical characteristic in rats, and try to explore the role of nitric oxide (NO).@*METHODS@#Rat model of restraint position was established. Rats were divided into control group, restraint position 12h and 24h groups. The markers of respiratory functions in vivo and the biomechanical markers of diaphragmatic characteristic ex vivo were evaluated. Serum NO levels were measured with spectrophotometry. The expressions of nNOS and iNOS mRNA in diaphragm were detected using RT-PCR.@*RESULTS@#Compared with control group, respiratory rate, tidal volume and minute ventilation were significantly decreased in the restraint position 12h and 24h groups. Pt of diaphragm significantly decreased and force-generating capacity reduced at low frequency stimulation in 12h group. Force-generating capacity over the full range reduced at low and high frequency stimulation in 24h group. Pt of diaphragm in control and restraint position groups increased after L-NNA pre-incubation. Force-frequency relationship after L-NNA pre-incubation reduced in 24h group. NO level in serum increased significantly in the restraint position groups. Diaphragmatic nNOS mRNA expression was upregulated significantly in the restraint position groups.@*CONCLUSION@#Restraint position induces the decreasement of diaphragmatic contractility and the decreasement is mediated by NO from diaphragm or circulation blood.

Mechanism of acute liver injury induced by crushing hindlimbs in rabbits / 法医学杂志

OBJECTIVE@#To investigate the role of oxidative stress in acute liver injury during crushing hindlimbs in rabbit.@*METHODS@#The crushing injury model in rabbit was established by intermittent crushing the hind limbs of rabbit with standard weight. The ALT and AST activities were spectrophotometrically measured. The weight ratio (wet/dry,W/D) of livers was measured with scale, and the pathologic changes were observed. Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and total anti-oxidant capacity (T-AOC) as well as malondialdehyde (MDA) level were spectrophotometrically measured.@*RESULTS@#As compared with control rabbits, crushing hindlimbs of rabbits induced acute liver injury with the increase in ALT and AST activities in serum,which were 4.31 (P < 0.01) and 10.54 times (P < 0.01) of control group respectively, there were cellular swellings and slight congestion of hepatic sinuses. In addition,crushing hind-limbs elicited significant decrease in SOD,CAT,GSH-Px activity and T-AOC to 17%, 29%, 24% and 21% (P < 0.01) compared with control group respectively, whereas MDA level markedly enhanced.@*CONCLUSION@#Crushing hindlimbs of rabbits induced acute liver injury and significant decrease in anti-oxidant capacity, the latter maybe play an important role in crushing hind-limbs of rabbits-elicited the acute liver injury.