Effect of lactulose on spinal cord ischemia-reperfusion injury in rats / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the effect of lactulose on spinal cord ischemia-reperfusion (I/R) injury in rats.Methods One hundred forty-four male Sprague-Dawley rats, aged 3 months, weighing 300-350 g, in which gastric tube was successfully inserted, were randomly divided into 4 groups (n=36 each) using a random number table sham operation group (group S), spinal cord I/R group (group I/R), lactulose group (group L), and lactulose + antibiotics group (group LA).Spinal cord ischemia was induced by occlusion of the thoracic aorta combined with controlled hypotension for 9 min, followed by reperfusion.Lactulose 0.5 g/kg was administered intragastrically immediately after onset of reperfusion in group L.Metronidazole 30 mg/kg and gentamicin 40 mg/kg were administered intragastrically three times a day during 1-3 days before operation in group LA, and the other procedures were similar to those previously described in group L.Hydrogen concentration in cerebrospinal fluid was detected before ischemia and at 10, 30, 60, 90, 120, 150 and 180 min after reperfusion.At 12, 24 and 48 h of reperfusion, 8 rats in each group were sacrificed, and the L3-5 segment of the spinal cord was isolated for determination of nuclear factor E2-related factor 2 (Nrf2) expression (by Western blot), superoxide dismutase (SOD) activity (by using xanthine oxidase method), catalase (CAT) activity (ammonium molybdate method), and 8-hydroxy-2'-deoxyguanosine (8-OHdG), 3-nitrotyrosine (3-NT) and malondialdehyde (MDA) contents (by ELISA).Neurological function was assessed and scored at 48 h of reperfusion.Six animals in each group were then sacrificed after assessment of neurological function, and the L3-5 segment of the spinal cord was removed for detection of apoptotic neurons.The cell survival rate and apoptotic rate were calculated.Results Compared with group S, no significant change was found in the hydrogen concentration in the cerebrospinal fluid at each time point, and in the level of Nrf2, CAT and SOD at 12, 24 and 48 h of reperfusion, the contents of 8-OHdG, 3-NT and MDA were significantly increased, the neurological scores and cell survival rate were decreased, and the apoptotic rate was increased in group I/R, and the hydrogen concentration in the cerebrospinal fluid at 30-180 min of reperfusion was increased, the level of Nrf2, CAT and SOD was increased at 12, 24 and 48 h of reperfusion, and no significant change was found in the contents of 8-OHdG, 3-NT and MDA, neurological scores, cell survival rate, and apoptotic rate in group L.Compared with group I/R, the hydrogen concentration in the cerebrospinal fluid at 30-180 min of reperfusion was increased, the level of Nrf2, CAT and SOD was increased, the contents of 8-OHdG, 3-NT and MDA were decreased, the neurological scores and cell survival rate were increased, and the apoptotic rate was decreased in group L, and no significant change was found in the parameters mentioned above in group LA.Conclusion Lactulose can reduce spinal cord I/R injury in rats.