[Protection of anisodamine on the mitochondrial injury induced by oxidative stress in swine with cardiac arrest].

Objective: To investigate the protection of anisodamine on cardiac ischemia/reperfusion (I/R) injury by oxidative stress by observing the changes in oxidation and antioxidant markers in plasma and myocardium, and the damage of cardiac mitochondria structure in pigs with cardiac arrest (CA).

Methods: Twenty-three healthy male swine were divided into three groups using random digits table: sham group (n=5), epinephrine group (n=9), and anisodamine group (n=9). The CA model was reproduced by alternating current. Blood samples were collected before CA, 8 minutes after CA, and 0 minute, 30 minutes, 24 hours after recovery of spontaneous circulation (ROSC), and hearts were harvested at 24 hours after ROSC. The content of malondialdehyde (MDA) and the enzyme activity of superoxide dismutase (SOD) were analyzed by spectrophotography, the cardiac ATP content was assayed by high performance liquid chromatography, the generation of reactive oxygen species (ROS) was detected by laser confocal microscope, and the myocardial ultrastructures were observed with transmission electron microscope to assess mitochondrial damage score.

Results: At 30 minutes and 24 hours after ROSC, plasma MDA level of anisodamine group was lower than that of epinephrine group (30 minutes: 43.38±8.12 μmol/L vs. 55.47±10.97 μmol/L, 24 hours: 29.96±6.04 μmol/L vs. 37.87±7.85 μmol/L, both P<0.05). Compared with epinephrine group, the cardiac SOD activity and ATP content of anisodamine group were elevated (SOD: 1.35±0.50 U/mg vs. 0.54±0.19 U/mg, ATP: 4.17±1.06 μmol/g vs. 2.95±0.94 μmol/g, P<0.01 and P<0.05), and the mitochondrial ROS level (RFU) was lowered (88.00±17.67 vs. 107.00±21.35, P<0.05). Although the cardiac MDA content was also reduced, but the difference between two resuscitation groups showed no statistical significance (16.66±2.89 μmol/mg vs. 19.28±3.90 μmol/mg, P>0.05). Using electron microscope, in epinephrine group disordered arrangement of cardiac myocyte arrangement was observed, and the mitochondrial alignment and morphology were significantly different from the sham group (mitochondrial damage score: 0.41±0.08 vs. 0.12±0.01, P<0.01). The level of mitochondrial injury in anisodamine group was milder than that of epinephrine group (mitochondrial damage score: 0.21±0.05 vs. 0.41±0.08, P<0.05).

Conclusion: Through regulating oxygen radical metabolism, anisodamine alleviates the injury to myocardial mitochondria structure and function injury as induced by oxidative stress.