ABSTRACT
Objective To observe the protein expression patterns of matrix metalloproteinase (MMP)-2 and MMP-9 in the liver tissue of liver contusion rats at different time after impact. Methods Fifty healthy adult male SD rats were randomly and evenly divided into control group and experimental groups (1 h, 3 h, 6 h, 12 h, 18 h, 24 h, 3 d, 5 d, 7 d after liver contusion). A rat liver contusion model was established by a free-falling device. The rats were killed at corresponding time, and the contused hepatic lobes were extracted. The protein expressions of MMP-2 and MMP-9 in contused liver tissue of the rats in each group were observed by immunohistochemical staining (SP method) and Western blotting. Results After the liver contusion, the expression of positive cell and the protein semiquantitative result showed that the protein expression of MMP-2 enhanced at 6 h and peaked at 24 h, then decreased gradually at 3-5 d, and returned to normal levels at 7 d. The difference of expression between group and its previous adjacent group after 6 h (except 18 h) had statistical significance (P<0.05). The protein expression of MMP-9 rose obviously at 1 h after liver contusion and peaked at 18 h, then decreased gradually at 3-7 d which still higher than control group. The expression difference between group and its previous adjacent group (except 12 h and 24 h) had statistical significance (P<0.05). Conclusion The protein expressions of MMP-2 and MMP-9 in contused liver tissue after impact show good time-dependent patterns, which may provide important reference indicators for the time estimation of liver contusion.
ABSTRACT
OBJECTIVE@#To investigate changes of LDH and HBDH activity in rabbit serum after non-thermal low voltage electrical injury and to provide diagnostic criteria for non-thermal low voltage electrical injury.@*METHODS@#Forty New Zealand rabbits were randomly distributed into control group and electrical injury group (EI-groups; designated 7 time points: 0 h, 2 h, 4 h, 12 h, 1 d, 2 d, 3 d), 5 rabbits per each group. EI-groups were treated with the method of non-thermal low voltage electrical injury established in our laboratory. Ventricular blood (5 mL) was obtained under anesthesia at designated time points after electrical injury. The activities of LDH and HBDH were measured.@*RESULTS@#Dynamic changes were observed with certain patterns from target serum enzyme activities after electrical injury. Compared with control group, the activities of LDH increased markedly at 4 h, 12 h, and on days 1, 2, and 3 after injury (4 h, 12 h, and day 1 P<0.01; day 2 and day 3 P<0.05). Activities of HBDH increased markedly at day 2 and day 3 after injury (P<0.05). The ratio of HBDH/LDH decreased markedly at 2 h, 4 h, and 12 h after injury (P<0.01).@*CONCLUSION@#Dynamic changes of LDH and HBDH activities may be useful in diagnosis of non-thermal low voltage electrical injury and in estimation of post injury intervals.