To investigate the damage against liver in different donation after cardiac death rat models and explore the underlying mechanisms.

Fifteen rats were equally divided into three groups: potassium chloride injection (PCI), diaphragmatic cutting (DC), apical clipping (AC) group. The PCL group was induced by intravenous injection of 10% potassium chloride solution to cardiac arrest through superficial dorsal vein of the penis. The DC group was made by clipping diaphragm to induce hypotension and hypoxia, and finally cardiac arrest. The AC group was made by clamping top of left and right ventricle of the heart with vascular clamp until cardiac arrest. The time of cardiac arrest was recorded. Serum was collected through postcava after cardiac death to evaluate liver function. Liver samples were collected and HE staining was performed. The level of nitric oxide (NO) and hydrogen peroxide (H₂O₂) were determined.The mRNA level of Bax, Bcl-2 and Caspase-3 were detected by RT-PCR and the protein level of p-Akt, Bax and Bcl-2 were detected by western blot. One-way ANOVA was used for comparing the time of cardiac arrest、liver function indexes、NO and H₂O₂ content in liver tissue、transcription levels of apoptosis-related molecules (Bax, Bcl-2, Capase-3) and related protein expressions between different groups. P<0.05 was considered statistically significant.

The time of cardiac arrest of DC and AC group were (720±137), (1 020±142) s respectively, longer than that in PCI group [(111±10) s, P all<0.05]. The serum levels of ALT in the PCI and DC group were (29±14)、(49±11) U/L, respectively, lower than that in AC group [(71±13) U/L, P all<0.05]. The serum levels of AST、glucose and lactate dehydrogenase in the AC group were (293±61), (26.7±6.6), (2 534±907) U/L, respectively, higher than those in PCI group [(131±67), (15.8±8.5), (1 528±1 170) U/L, P all<0.05]. The result of HE staining showed that the AC and DC groups suffered more serious congestion and red blood cell infiltration than that in PCI group, while there were no significant differences between the AC and DC group. The contents of H₂O₂ of PCI and DC group were (13.8±3.7), (13.7±1.8) mmol/L, lower than that in AC group [(19.1±4.1) mmol/L, P all <0.05]. The NO content in the AC group was (13.3±3.2) mmol/L, higher than that in DC group [(6.9±0.4) mmol/L, P all <0.05]. The mRNA level of Bax was found higher in DC group than that in PCL group. The expression of Bax in AC group was higher than that in the PCL group. There were marked increase of P-Akt 473 and P-Akt 308 expression in PCL group than AC group (P all<0.05).

The PCL group was considered the less damage to liver and its mechanism was probably associated with the cell apoptosis reduction and P-Akt pathway activation.