[The protective effects of ischemia preconditioning on the lung injury following with limbs ischemia/reperfusion].

OBJECTIVE: To explore the protective effects of ischemic preconditioning (IPC) on the lung injury following with limbs ischemia /reperfusion (LI/R). METHODS: The models of LI/R injury were constructed in rabbits. The blood from right external jugular vein and left common carotid artery, into and out-flowing pulmonary blood (IPB, OPB) respectively. Superoxide dismutase (SOD), malondialdehyde (MDA), nitric oxide (NO) in IPB and OPB and lung tissues were measured, as well as total nitric oxide synthase (tNOS) and inducible nitric oxide synthase (iNOS) in lung tissues were detected in different groups. The effects of IPC on the lung injury were observed. RESULTS: Compared with sham and before ischemic, the activity of SOD decreased and the content of MDA and NO increased after 4 h ischemia followed by 4 h reperfusion in IPB, OPB and lung tissues. The activity of tNOS and iNOS in lung tissues increased remarkably as well, there was statistical significance (P < 0.05, P < 0.01). SOD increased and MDA, NO, tNOS, iNOS decreased significantly by IPC before ischemia/reperfusion. The correlation analysis indicated that MDA was negatively correlated with SOD and was positively correlated with MDA, NO, iNOS (P < 0.01). CONCLUSION: Oxygen free radicals metabolic confusion of lung occurred in the course of LI/R, IPC could strengthen the resistance of peroxidation in lung and had protective effects on the lung injury following with LI/R.

[The affection and significance of NO on the expression of P-selectin in renal injury following hind limb ischemia/reperfusion in rats].

AIM: To probe into the affection and significance of NO on the expression of P-selectin in renal injury following hind limb ischemia/reperfusion in rats. METHODS: In accordance with the conventional approaches of our department, the model rats were prepared after they were made to undergo 4 hours or ischemia followed by 4 hours of reperfusion of hind limbs. The Wistar rats were divided into four groups randomly: Control group, LI/R group, L-Arg group and L-NAME group. And then in those four groups of Wistar rats, a series of values of measurement were determined such as: Plasma concentrations of nitric oxide (NO), blood urea nitrogen (BUN) and creatinine (Cr). Furthermore, biochemically there came to the assessment of the values including myeloperoxidase (MPO), NO, total nitric oxide synthase (tNOS), inducible NOS (iNOS) and constitutive NOS (cNOS) of renal tissue in different groups. By the methods of electrophoresis and biochemistry, the urine protein was mensurated. The immunohistochemical method was used to detect the expression of P-selectin protein. The morphologic changes were observed with a microscope. RESULTS: After hind limbs had suffered from ischemia/reperfusion for 4 hours, there was the occurrence of a series of results such as in the following which were based on the comparison between plasm of LI/R group and control group. The values of NO, BUN and Cr increased significantly, and the trend of indexes such as NO in renal tissue was similar to that in plasma. The values of MPO, tNOS and iNOS in renal tissue all increased significantly after reperfusion, while cNOS decreased distinctly. The urine protein appeared, especially large molecular weight protein. Renal pathology revealed that after LI/R there were edema and infiltration of polymorphonuclear neutrophil (PMN). Immunohistochemically, the expression of P-selectin was upregulated significantly. Compared with LI/R rats, all injury changes were alleviated in L-Arg group. Morphologic changes were mild. Both the content of urine protein and the percentage of apoptosis cell decreased. The expression of P-selectin was downregulated. In L-NAME group, all injury changes got worse. Immunohistochemical results showed strong positive staining of P-selectin. CONCLUSION: The renal injury after LI/R may relate to the strong expression of P-selectin. NO may have protective affection by decreasing the expression of P-selectin and alleviating the adhesion, aggregation and infiltration of neutrophils.

[Effects of shenmai injection on lipid peroxidation in the lung following with ischemia/ reperfusion (I/R) injury of limb].

AIM: To explore the effects of shenmai (Chinese transitional medicine) injection on lipid peroxidation in the lung following with ischemia/reperfusion (I/R) injury of limb. METHODS: The models of I/R injury of limb were constructed in rabbits. Superoxide dismutase (SOD) and malondialdehyde (MDA) in into and out-flowing pulmonary blood (IPB, OPB) and lung tissue were measured, as well as the effects of shenmai injection were observed. RESULTS: Compared with sham group, the activity of SOD in IPB, OPB and lung tissue were decreased, and the content of MDA was increased after 4 h ischemia followed by 4 h reperfusion. SOD increased and MDA decreased significantly by icy shenmai injection 30 min before reperfusion. The correlation analysis indicated that MDA was negatively correlated with SOD . CONCLUSION: Oxygen free radicals metabolic confusion of lung occurred in the course of I/R, shenmai injection can alleviate lipid peroxidation, get rid of free radicals and inhibit the damage of lung.

[Therapeutic effect of zinc sulfate on lung injury during superior mesenteric artery occlusion(SMAO) shock].

AIM: To study preventive and therapeutic effect of zinc sulfate on lung injury during superior mesenteric artery occlusion (SMAO) shock and their mechanism of action. METHODS: Model of rabbit SMAO shock was made. The effect of zinc sulfate on the malondialdehyde (MDA) in erythrocyte membrane and plasma, oxidase (XOD) in plasma, superoxide dismutase (SOD) in erythrocyte and MDA, SOD and pulmonary surfactant (PS) in lung tissues homogenate were observed. RESULTS: The administration of zinc sulfate decreased MDA and XOD, prevented the reduction of SOD and PS, and alleviated lung injury. CONCLUSION: It is suggested that lung is injured during SMAO shock and zinc sulfate possesses preventive and therapeutic effect, through stabilized membrane.

[Function of endothelin-1 in neurogenic pulmonary edema].

AIM: To investigate the role of endothelin-1 in the pathogenesis of neurogenetic pulmonary edema. METHODS: The levels of endothelin-1 in plasma and lung were measured in rats which suffered from diffuse brain injury on Marmarous' model. The changes of endothelin-1 in the lungs were also detected using an immunohistochemical method. RESULTS: After heavy diffuse brain injury in rats, the levels of endothelin-1 in plasma and lung began increasing at 1 hour, and peaked at 6 hour. Though a little declining at 24 hour, it maintained a higher level within 48 hours (P < 0.05). Pulmonary pathology showed that after brain injury there were congestion, swelling in pulmonary microvessels with broadened pulmonary interstitial tissue, and leucocyte infiltration was dominated by neutrophils and monocytes from 1 hour on, which peaked at 6 hour. More serious congestion, swelling and protein effusion in pulmonary alveoli were observed at both 24 h and 48 h. Immunohistochemically, endothelin-1 had more significant expression and higher levels of OD in the experimental groups than that in the control's, the most significance of which was at 6 hour. CONCLUSION: The inflammatory injury mechanism caused by endothelin-1 may play an important role in neurogenic pulmonary edema.

[Influence of astragalus and zinc sulfate on the viscosity in erythrocyte membrane during intestinal ischemia - reperfusion(I/R) injury].

AIM: To study the influence of astragalus and zinc sulfate on the viscosity in erythrocyte membrane during intestinal I/R and their mechanism of action. METHODS: Models of rabbits intestinal I/R injury were made. The effect of astragalus and zinc sulfate on the viscosity and malondialdehyde (MDA) in erythrocyte membrane, superoxide dismutase (SOD) in erythrocyte, oxidase (XO) in plasma and MDA tissues homogenate were observed. RESULTS: The administration of astragalus and zinc sulfate decreased viscosity and MDA and XO, prevented the reduction of SOD, and alleviated I/R injury. CONCLUSION: Lipid peroxidation injury of the erythrocyte membrane was one of the pathogenesis of I/R injury, and astragalus and the zinc sulfate possessed effects of anti-lipid peroxide, stabilized erythrocyte membrane, increased red blood cell deform ability and raised microcircular perfusion.