ABSTRACT
<p><b>OBJECTIVE</b>To investigate the effect of aloe polysaccharides pretreatment on the cerebral inflammatory response and lipid peroxidation in severe hemorrhagic shock rats first entering high altitude.</p><p><b>METHODS</b>Forty healthy male SD rats weighing 250-300 g were randomly divided into 5 groups (n = 8 each): sham group, shock group, AP group was further divided into 3 subgroups (AP1 0.75 mg/kg; AP2 1.50 mg/kg; AP3 3.00 mg/kg). The different doses AP were given iv respectively at 30 min before hemorrhagic shock. The mean blood pressure (MAP) was maintained at (35 ± 5) mmHg (1 mmHg = 0.133 kPa) for 60 minutes. The animals were killed at 2 hours after resuscitation. Blood samples were obtained from femoral artery for detecting tumor necrosis factor α (TNF-α), IL-6 and IL-10 concentrations; the frontal and parietal lobes brain and the hippocampus were separated from brain tissues on the ice for detecting superoxide dismutase (SOD) activity and myeloperoxidase (MPO) activity, malondialdehyde (MDA) concentration, brain Wet-dry weight ratio (W/D).</p><p><b>RESULTS</b>Compared with sham group, hemorrhagic shock significantly increased serum TNF-α ((76 ± 11) ng/L), IL-6 ((1303 ± 141) ng/L) and IL-10 concentrations ((95 ± 14) ng/L), MPO activity ((20.72 ± 2.28)×10(-2) U/g) and MDA concentration ((80 ± 13) nmol/mgprot) in the brain tissue and brain W/D (6.21 ± 0.18) (t = 6.928 - 14.565, P < 0.05), while SOD activity ((56 ± 11) U/mgprot) decreased significantly (t = -5.374, P < 0.05). There were no significant difference between shock and AP1 groups. AP2 group significantly inhibited hemorrhagic shock-induced increase serum TNF-α ((54 ± 12) ng/L), IL-6 ((846 ± 78) ng/L) and IL-10 concentrations ((66 ± 11) ng/L), MPO activity ((13.13 ± 1.23)×10(-2) U/g) and MDA concentration ((56 ± 9) nmol/mgprot) in the brain tissue and brain W/D (5.71 ± 0.18) (t = -6.905 - -3.357, P < 0.05), while SOD activity ((86 ± 12) U/mgprot) increased significantly compared to shock group (t = 4.240, P < 0.05). There were no significant difference between AP2 and AP3 groups.</p><p><b>CONCLUSION</b>AP pretreatment can attenuate the cerebral ischemia and reperfusion injury in severe traumatic-hemorrhagic rats first entering high altitude through inhibiting systemic inflammatory response and leukocyte aggregation and lipid peroxidation in the brain.</p>
Subject(s)
Animals , Male , Rats , Aloe , Chemistry , Altitude , Brain , Metabolism , Pathology , Brain Ischemia , Drug Therapy , Disease Models, Animal , Interleukin-10 , Blood , Interleukin-6 , Blood , Lipid Peroxidation , Malondialdehyde , Metabolism , Polysaccharides , Pharmacology , Rats, Sprague-Dawley , Reperfusion Injury , Drug Therapy , Shock, Hemorrhagic , Metabolism , Pathology , Superoxide Dismutase , Metabolism , Tumor Necrosis Factor-alpha , BloodABSTRACT
<p><b>OBJECTIVE</b>To study the effects of limb ischemia preconditioning on pulmonary free radicals and cytokine levels during lung ischemia-reperfusion injury in rabbits.</p><p><b>METHODS</b>Eighteen healthy rabbits were randomly divided into three groups: control group (group C, n = 6), ischemia/reperfusion group (group I/R, n = 6), limb ischemia preconditioning group (group L, n = 6). At the end of experiments, the wet to dry-weight ratio (W/D), activities of superoxide dismutase (SOD) and myeloperoxidase (MPO), levels of malondialdehyde (MDA) and the contents of cytokines (TNF-α, IL-6, IL-8 and IL-10) were determined in lung tissues. Protein levels of bronchoalveolar lavage fluid and serum were measured to calculate the lung permeability index. Pathologic changes of lung tissues were also observed.</p><p><b>RESULTS</b>Compared to the group I/R, the lung tissue W/D ratio, MPO activity, lung permeability index, MDA and the cytokines (TNF-α, IL-6 and IL-8) levels were significantly decreased in group L (P < 0.05), while the SOD activity (P < 0.05) and IL-10 contents were significantly increased (P < 0.01). There was no statistical difference in the changes of the above parameters between group L and group C (P > 0.05). The morphologic damages were significantly reduced in group L than that in group I/R.</p><p><b>CONCLUSION</b>Limb ischemia preconditioning has protective effect against lung ischemia-reperfusion injury, which may at least in part through inhibiting the release of oxygen-derived free radicals and pro-inflammatory cytokines (TNF-α, IL-6, IL-8) and increasing the production of anti-inflammatory cytokine IL-10.</p>