Shexiang Baoxin Pill Attenuates Ischemic Injury by Promoting Angiogenesis by Activation of Aldehyde Dehydrogenase 2.

ABSTRACT: Promoting angiogenesis is a critical treatment strategy for ischemic cardiovascular diseases. Shexiang Baoxin Pill (SBP), a traditional Chinese medicine, has been reported to be capable of relieving angina and improve heart function by promoting angiogenesis. The aim of this study was to determine the role of mitochondrial aldehyde dehydrogenase 2 (ALDH2) in SBP-induced angiogenesis. Left femoral artery ligation was performed in wild-type mice (WT) and ALDH2 knockout mice, which were administrated with SBP (20 mg/kg/d) or equal volume saline per day by gastric gavage for 2 weeks. Perfusion recovery, angiogenesis in chronic hind limb ischemia, was significantly improved in the WT + SBP group than in the WT group. However, these beneficial effects were absent in ALDH2 knockout mice. In vitro, hypoxia impaired the ability of proliferation, migration and tube formation, sprouting angiogenesis, and promoted apoptosis in cardiovascular microvascular endothelial cells, whereas the hypoxia damage was restored by SBP. The protective effect of SBP was remarkably weakened by ALDH2 knockdown. Furthermore, SBP suppressed hypoxia-induced ALDH2/protein kinase B (AKT)/mammalian target of rapamycin pathways. In conclusion, this study demonstrated that SBP protected lower limb from ischemia injury through the ALDH2-dependent pathway. The protective mechanism of SBP in cardiovascular microvascular endothelial cells was partly mediated through ALDH2/AKT/mammalian target of rapamycin pathways.

Is Chronic Curcumin Supplementation Neuroprotective Against Ischemia for Antioxidant Activity, Neurological Deficit, or Neuronal Apoptosis in an Experimental Stroke Model?

AIM: To investigate the neuroprotective effect of chronic curcumin supplementation on the rat forebrain prior to ischemia and reperfusion. MATERIAL AND METHODS: Forebrain ischemia was induced by bilateral common carotid artery occlusion for 1/2 hour, followed by reperfusion for 72 hours. Older rats were divided into five groups: Group I received 300 mg/kg oral curcumin for 21 days before ischemia and 300 mg/kg intraperitoneal curcumin after ischemia; Group II received 300 mg/kg intraperitoneal curcumin after ischemia; Group III received 300 mg/kg oral curcumin for 21 days before ischemia; Group IV had only ischemia; Group V was the sham-operated group. The forebrain was rapidly dissected for biochemical parameter assessment and histopathological examination. RESULTS: In forebrain tissue, enzyme activities of superoxide dismutase, glutathione peroxidase, and catalase were significantly higher in Group I than Groups II or III (p < 0.05) while xanthine dehydrogenase and malondialdehyde enzyme activities and concentrations of interleukin-6 and TNF-alpha were significantly lower in Group I when compared to Groups II and III (p < 0.05). A significant reduction in neurological score was observed after 24 and 72 hours in the curcumin-treated groups compared with the ischemic group. We also found a marked reduction in apoptotic index after 72 hours in the groups receiving curcumin. Significantly more TUNEL-positive cells were observed in the ischemic group compared to those treated with curcumin. CONCLUSION: We demonstrated the neuroprotective effect of chronic curcumin supplement on biochemical parameters, neurological scores and apoptosis following ischemia and reperfusion injury in rats.

Sirtuin 1-mediated inhibition of p66shc expression alleviates liver ischemia/reperfusion injury.

OBJECTIVES: Ischemia/reperfusion is a leading cause of liver damage after surgical intervention, trauma, and transplantation. It has been reported that the nicotinamide adenine dinucleotide-dependent deacetylase sirtuin 1 attenuates myocardial, cerebral, and renal ischemia/reperfusion damage. This study aimed to investigate the involvement of sirtuin 1-mediated p66shc inhibition in liver ischemia/reperfusion and explore the effect of carnosic acid and ischemic preconditioning on liver ischemia/reperfusion-induced damage. DESIGN: Laboratory investigation. SETTING: University laboratory. SUBJECTS: Male Sprague-Dawley rats and HepG2 cells. INTERVENTIONS: The rats were subjected to 45 minutes of ischemia to 70% of the liver, followed by 3-hour reperfusion. The HepG2 cells were subjected to hypoxia/reoxygenation-induced injury. MEASUREMENTS AND MAIN RESULTS: In the rats with liver ischemia/reperfusion injury, carnosic acid pretreatment and ischemic preconditioning dramatically reduced the serum aminotransferase activity and proinflammatory chemokine levels and improved the liver histological evaluations. Carnosic acid and ischemic preconditioning also increased manganese superoxide dismutase and Bcl-xL, but down-regulated cleaved caspase-3. Interestingly, the protective effect of carnosic acid and ischemic preconditioning was positively associated with sirtuin 1 activation. By contrast, p66shc, a kinase that promotes oxidative injury and apoptosis, was inhibited by carnosic acid and ischemic preconditioning. Sirtuin 1 small interfering RNA knockdown experiments confirmed that carnosic acid increased sirtuin 1-mediated repression of p66shc in HepG2 cells and that the protective effect of carnosic acid against hypoxia/reoxygenation injury was inhibited by the sirtuin 1 inhibitor nicotinamide. These results suggest that carnosic acid protects hepatocytes from hypoxia/reoxygenation damage through sirtuin 1-mediated p66shc suppression. To support this notion, we further demonstrated that the sirtuin 1 activator resveratrol achieved a protective effect similar to that of carnosic acid against hypoxia/reoxygenation injury, whereas sirtuin 1 small interfering RNA and nicotinamide had the opposite effect. CONCLUSIONS: Carnosic acid and ischemic preconditioning protect against ischemia/reperfusion-induced liver injury. Mechanistically, the protective effect involves the sirtuin 1-mediated inhibition of p66shc, suggesting that this pathway is a novel potential therapeutic target for protecting the liver from ischemia/reperfusion injury.

Preconditioning somatothermal stimulation on Qimen (LR14) reduces hepatic ischemia/reperfusion injury in rats.

BACKGROUND: In human beings or animals, ischemia/reperfusion (I/R) injury of the liver may occur in many clinical conditions, such as circulating shock, liver transplantation and surgery and several other pathological conditions. I/R injury has a complex pathophysiology resulting from a number of contributing factors. Therefore, it is difficult to achieve effective treatment or protection by individually targeting the mediators. This study aimed at studying the effects of local somatothermal stimulation preconditioning on the right Qimen (LR14) on hepatic I/R injury in rats. METHODS: Eighteen male Sprague-Dawley rats were randomly divided into three groups. The rats were preconditioned with thermal tolerance study, which included one dose of local somatothermal stimulation (LSTS) on right Qimen (LR14) at an interval of 12 h, followed by hepatic ischemia for 60 min and then reperfusion for 60 min. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) have been used to assess the liver functions, and liver tissues were taken for the measurements such as malondialdehyde (MDA), glutathione (GSH), catalase (CAT), superoxidase dismutase (SOD), and myeloperoxidase (MPO). RESULTS: The results show that the plasma ALT and AST activities were higher in the I/R group than in the control group. In addition, the plasma ALT and AST activities decreased in the groups that received LSTS. The hepatic SOD levels reduced significantly by I/R injury. Moreover, the hepatic MPO activity significantly increased by I/R injury while it decreased in the groups given LSTS. CONCLUSIONS: Our findings show that LSTS provides a protective effects on the liver from the I/R injury. Therefore, LSTS might offer an easy and inexpensive intervention for patients who have suffered from I/R of the liver especially in the process of hepatotomy and hepatic transplantation.

S100A1 deficiency impairs postischemic angiogenesis via compromised proangiogenic endothelial cell function and nitric oxide synthase regulation.

RATIONALE: Mice lacking the EF-hand Ca2+ sensor S100A1 display endothelial dysfunction because of distorted Ca2+ -activated nitric oxide (NO) generation. OBJECTIVE: To determine the pathophysiological role of S100A1 in endothelial cell (EC) function in experimental ischemic revascularization. METHODS AND RESULTS: Patients with chronic critical limb ischemia showed almost complete loss of S100A1 expression in hypoxic tissue. Ensuing studies in S100A1 knockout (SKO) mice subjected to femoral artery resection unveiled insufficient perfusion recovery and high rates of autoamputation. Defective in vivo angiogenesis prompted cellular studies in SKO ECs and human ECs, with small interfering RNA-mediated S100A1 knockdown demonstrating impaired in vitro and in vivo proangiogenic properties (proliferation, migration, tube formation) and attenuated vascular endothelial growth factor (VEGF)-stimulated and hypoxia-stimulated endothelial NO synthase (eNOS) activity. Mechanistically, S100A1 deficiency compromised eNOS activity in ECs by interrupted stimulatory S100A1/eNOS interaction and protein kinase C hyperactivation that resulted in inhibitory eNOS phosphorylation and enhanced VEGF receptor-2 degradation with attenuated VEGF signaling. Ischemic SKO tissue recapitulated the same molecular abnormalities with insufficient in vivo NO generation. Unresolved ischemia entailed excessive VEGF accumulation in SKO mice with aggravated VEGF receptor-2 degradation and blunted in vivo signaling through the proangiogenic phosphoinositide-3-kinase/Akt/eNOS cascade. The NO supplementation strategies rescued defective angiogenesis and salvaged limbs in SKO mice after femoral artery resection. CONCLUSIONS: Our study shows for the first time downregulation of S100A1 expression in patients with critical limb ischemia and identifies S100A1 as critical for EC function in postnatal ischemic angiogenesis. These findings link its pathological plasticity in critical limb ischemia to impaired neovascularization, prompting further studies to probe the microvascular therapeutic potential of S100A1.

Waon therapy upregulates Hsp90 and leads to angiogenesis through the Akt-endothelial nitric oxide synthase pathway in mouse hindlimb ischemia.

BACKGROUND: Thermal therapy, namely Waon therapy, has previously been reported to regulate nitric oxide (NO) and endothelial NO synthase (eNOS) and augment ischemia-induced angiogenesis in mice and improve limb ischemia in patients with peripheral artery disease. The aim of this study was to clarify the precise mechanism by which Waon therapy augments angiogenesis in mice with hindlimb ischemia. METHODS AND RESULTS: Unilateral hindlimb ischemia was induced in apolipoprotein E-deficient mice and Waon therapy was performed for 5 weeks. Heat shock protein 90 (Hsp90), phosphorylated-Akt, and phosphorylated-eNOS were detected in arterial endothelial cells of ischemic hindlimbs and all were upregulated by Waon therapy compared to controls. Waon therapy also increased serum concentrations of nitrite and nitrate. Capillary density and the ischemic limb/normal side blood perfusion ratio monitored by laser Doppler perfusion imaging in the Waon therapy group were significantly increased beyond those in the control group. The effect of Waon therapy on angiogenesis through the activation of the Hsp90/Akt/eNOS pathway was attenuated by the administration of a Hsp90 inhibitor. CONCLUSIONS: It is suggested that Waon therapy upregulates Hsp90, which contributes to the activation of the Akt/eNOS/NO pathway, and induces angiogenesis in mice with hindlimb ischemia.

Aqueous extract of the medicinal plant Patrinia villosa Juss. induces angiogenesis via activation of focal adhesion kinase.

Patrinia villosa, a Chinese medicinal herb, is known for its anti-inflammatory effects. In the present study, we tested the pro-angiogenic efficacy of an aqueous extract of Patrinia villosa (PVE) in vitro and in vivo. Treatment with PVE significantly enhanced cell proliferation, migration, and the capillary-like structure forming activity of cultured human umbilical vein endothelial cells (HUVECs). Western blot analysis demonstrated that PVE treatment induced a time-dependent phosphorylation of FAK and Akt in HUVECs. Preincubation with a FAK inhibitor, SC203950, abolished PVE-induced proliferation of HUVECs, indicating a role for FAK in PVE-induced angiogenesis. The proangiogenic activity of PVE was confirmed by an ex vivo mouse aortic ring assay and an in vivo murine hindlimb ischemia model. Further analysis using fractions of PVE partitioned by n-hexane, EtOAc, n-BuOH, and water residue revealed that the EtOAc fraction contains the bioactive components responsible for PVE-induced migration, endothelial cord formation, FAK phosphorylation, and aortic ring sprouting. Our results provide a rationale for the use of PVE in the treatment of peripheral vascular insufficiency; they indicate the need to identify the novel pro-angiogenic chemicals in the fractions of PVE.

Taurine reduces caspase-8 and caspase-9 expression induced by ischemia in the mouse hypothalamic nuclei.

Taurine is a sulphur-containing amino acid abundant in the nervous system. It protects cells from ischemia-induced apoptosis, but the mechanism underlying this is not well established. The aim of our study was to explore the effects of taurine on two main pathways of apoptosis induced by ischemia: receptor-mediated and mitochondrial cell death. Brain slices containing the supraoptic (SON) and paraventricular (PVN) nuclei of the hypothalamus were incubated in vitro under control and simulated ischemic (oxygen-glucose deprivation for 30 min) conditions in the absence and presence of 20 mM taurine. Brain slices were harvested after the 180-min "postischemic" period and fixed in 4% paraformaldehyde. To estimate apoptosis, immunostaining was done for caspase-8 and caspase-9 in paraffin-embedded sections. Immunoreactive caspase-8 and caspase-9 cells were observed in SON and PVN in all experimental groups, but in the "ischemic" group the expression of caspase-8 and caspase-9 and the number of immunoreactive cells was significantly increased in both hypothalamic nuclei. Addition of taurine (20 mM) to the incubation medium induced a marked decrease in caspase-8 and caspase-9 immunoreactivity after ischemia in SON and PVN when compared with the taurine-untreated "ischemic" group. Taurine reduces ischemia-induced caspase-8 and caspase-9 expression, the key inductors of apoptosis in SON and PVN.

Inhibition of cyclooxygenase-2 expression by zinc-chelator in retinal ischemia.

The zinc ion (Zn2+) is abundant in neurons. However, excessive Zn2+ can induce neuronal cell death. This study examined the role of Zn2+ in transient retinal ischemia in adult male rats. The rats were sacrificed 4-24 h after retinal ischemia by high intra-ocular pressure, and the retinas were prepared for microscopic examination of retinal cell degeneration, and fluorescence microscopy using zinquin ethyl ester as the zinc ion-specific probe. Moreover, COX-2 expression was observed by Western blotting. In control retinas, there was a low Zn2+ concentration in the inner plexiform layer (IPL), a high Zn2+ concentration in the outer plexiform layer (OPL), and no detectable Zn2+ in either the ganglion cell layer (GCL) or the inner nuclear layer (INL). In contrast, in the retinas exposed to ischemia without the administration of the zinc ion chelators (Ca2+-EDTA and TPEN), Zn2+ deposits were found in the IPL and INL beginning 4 h after ischemia and degeneration of neurons was found in the GCL and INL. Less Zn2+ accumulation in the IPL and INL and less neuronal degeneration in the GCL and INL were found in the retinas treated with Ca2+-EDTA or TPEN before ischemia. Furthermore, the COX-2 protein levels increased 4-8 h after retinal ischemia, and chelation of zinc ion inhibited this effect. These results suggest that the accumulation of Zn2+ following an ischemic insult can cause retinal degeneration and induce abnormal COX-2 expression.

Inhibition of nNOS and COX-2 expression by lutein in acute retinal ischemia.

OBJECTIVE: Lutein is a major nutrient in the retina. Lutein has an antioxidative effect and protects against macular degeneration and retinal degenerative disease. However, the mechanism of lutein is not clear in retinal degeneration, and a role for lutein is not known in ischemic injury. In this study, an ischemia-induced rat retina was examined to determine the effect of the lutein on ischemic retinal cell death. METHODS: We used a transient ischemia model of high intraocular pressure in the rat. Lutein (Kemin Foods, LC) was injected into the intraperitoneal or intravitreous before ischemia. Retinal degeneration was observed by light microscopy 24 h after ischemia. Expressions of neuronal nitric oxide synthase (nNOS) and cyclo-oxygenase-2 (COX-2) were detected by western blot analysis at various times after retinal ischemia. RESULTS: The nNOS and COX-2 expression levels were increased early in ischemic control retinas, but these increases were inhibited by lutein. In addition, the inhibitory effect of lutein was observed to be dose dependent. Further, ischemia-induced cell death was inhibited by lutein. Lutein-injected ischemic retina appeared similar to normal retina. CONCLUSION: This study investigated the protective effect of lutein on retinal ischemia and the inhibitory effect of nNOS and COX-2 expressions. These results suggest that a supplement with lutein may have the potential to inhibit ischemic cell death by this mechanism in the neural retina.

Arachidonic acid epoxygenase metabolites stimulate endothelial cell growth and angiogenesis via mitogen-activated protein kinase and phosphatidylinositol 3-kinase/Akt signaling pathways.

Cytochrome P450 arachidonic acid (AA) epoxygenase metabolites, the epoxyeicosatrienoic acids (EETs), dilate arteries via hyperpolarization of smooth muscle cells and also have nonvasodilatory effects within the vasculature. The present study investigated the angiogenic effects of endogenous and exogenous EETs and the relevant signaling mechanisms involved. Bovine aortic endothelial cells (BAECs) were incubated with synthetic EETs or infected with recombinant adeno-associated viruses (rAAVs) containing CYP2C11-NADPH-cytochrome P450 oxidoreductase (CYPOR), CYP2J2, or CYP102 F87V mutant to increase endogenous levels of EETs. The following endpoints were measured: BAEC proliferation, migration, capillary formation, and in vivo angiogenesis. The potential involvement of various signaling pathways was explored using selective inhibitors. The results showed that transfection with either rAAV-CYP2C11-CYPOR, rAAV-CYP2J2, or rAAV-CYP102 F87V, or incubation with EETs promoted BAEC proliferation, increased migration of BAECs as assessed by Transwell analysis and wound healing assays, and enhanced capillary tubule formation as determined by chicken embryo chorioallantoic membrane assays and tube formation tests on matrigel. The effects of EETs on proliferation, migration, and capillary tubule formation were attenuated by inhibitors of mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3 (PI3)-kinase/Akt pathways and partially attenuated by an endothelial nitric-oxide synthase (eNOS) inhibitor but not by a protein kinase C inhibitor. In a rat ischemic hind limb model, rAAV-mediated AA epoxygenase transfection induced angiogenesis. We conclude that AA epoxygenase metabolites can promote angiogenesis, which may provide protection to ischemic tissues. The results also suggest that the angiogenic effects of EETs involve the MAPK and PI3-kinase/Akt signaling pathways, and to some extent, the eNOS pathway.

Ozone therapy and the activity of selected lysosomal enzymes in blood serum of patients with lower limb ischaemia associated with obliterative atheromatosis.

BACKGROUND: The paper compares the effects of ozone therapy and conventional balneological methods on health condition of patients with obliterative atheromatosis and on serum activity of three lysosomal enzymes. MATERIAL/METHODS: Sixty-four patients with lower limb ischaemia in the course of obliterative atheromatosis (without diabetes) were enrolled in the study. Thirty-two patients were treated with ozone administered by intravenous infusions and 30-minute aerosol oxygen-ozone baths. A comparative group was formed of 32 patients treated with traditional balneology. There was also a control group made up of 30 healthy subjects. Ozone therapy as well as traditional balneology were administered daily for the period of 10 days, excluding Saturdays and Sundays. Blood for biochemical analysis was collected from elbow vein in the following time intervals: 24 hours before ozone therapy or classical balneology, one hour after therapy and on the 10th day of treatment. The activity of cathepsin D, acid phosphatase and arylsulphatase as well as the levels of a-1-antitrypsin (protease inhibitor) were determined in blood serum of patients with obliterative atheromatosis. RESULTS: In patients who received ozone therapy the activity of analysed lysosomal hydrolases returned to the values typical for healthy subjects. Patients' general condition also improved. The use of traditional balneological methods did not result in any significant change either in the activity of lysosomal hydrolases, the level of a-1-antitrypsin or general condition of patients. CONCLUSIONS: Ozone therapy administered by intravenous infusions and aerosol oxygen-ozone baths of lower extremities yields much better therapeutic results in comparison with classical balneology.

Importance of lipid peroxidation, protective enzymes and trace elements in chronic leg ischaemia.

The aim of this study was to assess the lipid peroxidation in chronic leg ischaemia by determining thiobarbituric acid reactants. Furthermore, Cu, Zn-superoxide dismutase and glutathione peroxidase activities as well as the trace element profile (Zn, Cu, Se, Mg) were determined. Fasting blood samples from the common femoral artery and vein were taken from both legs of 15 patients (57 +/- 7 years) with peripheral arteriosclerosis and 9 individuals (54 +/- 9 years) of the control group without chronic leg ischaemia. Patients with peripheral arteriosclerosis showed significantly decreased venous thiobarbituric acid reactant levels (2.01 +/- 0.37 vs. 2.39 +/- 0.59 mumol/l in controls, p < 0.05). Both arterial and venous samples from patients showed lower Cu, Zn-superoxide dismutase activities and higher glutathione peroxidase activities than controls. Venous activities of glutathione peroxidase were significantly higher than arterial activities in both groups (patients 0.52 +/- 0.18 vs 0.43 +/- 0.15 mukat/g Hb, p < 0.001, control group 0.51 +/- 0.12 vs 0.39 +/- 0.19 mukat/g Hb, p < 0.01). The trace element profile of the patients showed a highly significant decrease in magnesium levels (p < 0.001) and increased venous copper levels (p < 0.05). No significant changes were found in zinc and selenium levels. The results of this study show that during chronic leg ischaemia the production of free oxygen radicals at rest is well controlled, but the activity of antioxidant enzymes seems to be impaired.

Role of P-selectin in total hepatic ischemia and reperfusion.

BACKGROUND: Ischemia and reperfusion of the liver are associated with changes in the interaction of leukocyte-endothelium cells. The role of an adhesion molecule, P-selectin, is studied in ischemia and reperfusion injury of the liver. STUDY DESIGN: Total hepatic ischemia was produced in the rat for 90 minutes, using a portosystemic shunt. To determine the role of P-selectin in ischemia and reperfusion, a murine IgG1 monoclonal antibody to P-selectin (1 mg/kg) was used at different times (30 minutes before and at reperfusion and five minutes and 24 hours after reperfusion). Rats survived for seven days, and tests showing hepatic injury, myeloperoxidase in hepatic tissue, and histologic studies were analyzed at four hours postreperfusion. RESULTS: Survival improved from 15 percent for the rats in the ischemia control group to 55 percent for those in the group receiving anti-P-selectin antibody given 30 minutes before reperfusion (p < 0.05). We observed an improved statistically significant difference in tests demonstrating hepatic injury, myeloperoxidase in hepatic tissue, and histologic studies in the treated and ischemia control groups. The other groups did not show consistent significant differences. CONCLUSIONS: P-selectin has a significant role in ischemia and reperfusion injury of the liver. Early modulation of the interaction between P-selectin and its ligand decreased neutrophil adhesion and migration and consequently diminished damage to the liver.

[The effect of low-intensity laser radiation on the regional hemodynamics in strangulated intestinal obstruction]. / Vliianie nizkointensivnogo lazernogo izlucheniia na regionarnuiu gemodinamiku pri stranguliatsionnoi neprokhodimosti kishechnika.

In the experiment on 214 white rats, the effect of different types of low-intensive laser irradiation and existing methods of treatment on regional hemodynamics in strangulated ileus was studied. Combined use of ultraviolet and helium-neon lasers has to be proved to be the most effective. Ultraviolet laser irradiation contributed to increase in elasticity of the arterial wall and cupping off the vascular spasm, helium-neon irradiation had a stimulating effect on the tissues of the intestinal wall.

Normothermic liver ischemia in rats: xanthine oxidase is not the main source of oxygen free radicals.

We studied the effect of allopurinol (ALL) on the activity of xanthine dehydrogenase (XDH), xanthine oxidase (XOX), superoxide dismutase (SOD), and catalase (CAT) in rat liver during ischemia followed by 60 min of reperfusion. We induced 60-min ischemia in the median and left lobes by clamping the hepatic artery and portal branches. The percentage XOX relative to total oxidase activity increased significantly in the control group, from 10% during the stabilization period to 18% after 60 min of reperfusion. The XDH activity decreased during reperfusion. Activity of both XDH and XOX was almost completely blocked by ALL. The activity of SOD and CAT did not differ significantly between the ALL group and controls after 60 min of reperfusion. ALL treatment did not affect liver injury parameters, as concentrations of lactate dehydrogenase (LDH) and alanine transferase (ALT) increased in plasma after ischemia, both in controls and in the ALL-treated group. We concluded that ischemia promotes conversion of XDH to XOX during reperfusion. XOX may not be the main source of free radical production, since intracellular scavengers (SOD and CAT) did not differ significantly between controls and the ALL-treated group, despite the fact that ALL blocked XOX activity completely.

Role of xanthine oxidase in postischemic microvascular injury in skeletal muscle.

Previous reports indicate that allopurinol, a xanthine oxidase inhibitor, attenuates the microvascular injury produced by reperfusion of ischemic skeletal muscle. To further assess the role of xanthine oxidase in ischemia/reperfusion (I/R) injury, we examined the effect of xanthine oxidase depletion or inhibition on the increase in microvascular permeability produced by I/R. Changes in vascular permeability were assessed by measurement of the solvent drag reflection coefficient for total plasma proteins (sigma) in rat hindquarters subjected to 2 h of ischemia and 30 min of reperfusion in xanthine oxidase-replete and -depleted animals and in animals pretreated with the xanthine oxidase inhibitor oxypurinol. Xanthine oxidase depletion was accomplished by administration of a tungsten-supplemented (0.7 g/kg diet), molybdenum-deficient diet. In animals fed the tungsten diet, muscle total xanthine dehydrogenase plus xanthine oxidase activity was decreased to less than 10% of control values. Estimates of sigma averaged 0.85 +/- 0.04 in nonischemic (continuous perfusion for 2.5 h) hindquarters, whereas muscle xanthine oxidase activity averaged 3.3 +/- 0.4 mU/g wet wt. I/R was associated with a marked decrease in sigma (0.54 +/- 0.02), whereas xanthine oxidase activity was increased to 5.8 +/- 0.5 mU/g wet wt. These results indicate that I/R produced a dramatic increase in vascular permeability coincident with an increase in muscle xanthine oxidase activity. Xanthine oxidase depletion with the tungsten diet or pretreatment with oxypurinol attenuated this permeability increase (sigma = 0.72 +/- 0.03 and 0.77 +/- 0.7, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of FDP and Danshen on renal cortical Na-K-ATPase activity in rats after treatment with renal ischemia and gentamicin.

The main purpose of our study is to investigate the possible protective effects of Fructose 1-6 diphosphate (FDP) and Danshen (Salvia Miltiozzhiza Bunze) on renal cortical Na-K-ATPase activity after renal ischemia and gentamicin nephrotoxicity. An 18.6% reduction in renal cortical Na-K-ATPase activity was shown after 30 min of renal pedicle clamping and 60 min of reflow, and a 32.5% reduction after 90 min of single injection of 100 mg/kg gentamicin. Light and electronic microscopy revealed no significant morphologic changes in both groups in the experiment. 4g/kg FDP and 18g/kg Danshen were infused 60 min after reflow in the ischemic group, 90 min after injection of gentamicin in the gentamicin-treated group and 90 min in the sham-operated group separately. The enzyme activity in the FDP-treated groups was found to be higher than that in the control kidneys while in the Danshen-treated groups no significant difference could be found. Our study showed that FDP and Danshen could prevent the decline of renal cortical Na-K-ATPase activity induced by ischemia and gentamicin. FDP could increase this enzyme activity while Danshen showed no such direct effect.

[Functional biochemical changes and their pharmacologic correction by pirroksan in renal ischemia]. / Funktsional'no-biokhimicheskie izmeneniia i ikh farmakologicheskaia korrektsiia pirroksanom pri ishemii pochek.

Bilateral one-hour ischemia of the kidneys in rats causes essential metabolic shifts in the renal tissues, and diminished intensity of the energetic status as a result of which the intactness of the cell membranes and the main functions of the nephron are disturbed. Pharmacological correction of postischemic disorders by the alpha-adrenergic blocking agent pyrroxane increases the activity of oxidative processes and intensifies the glycolysis rate. Improvement of the energy provision of the nephron function occurs in parallel with restoration of the diuresis level and processes of filtration and reabsorption.

Effect of superoxide dismutase on liver ischemia-reperfusion injury in the rat: a biochemical monitoring.

Oxygen free radicals have been implicated in the pathogenesis of postischemic liver injury. High-dose superoxide dismutase (SOD), a radical scavenging enzyme, has been investigated in a rat model of liver ischemia reperfusion by biochemical monitoring. Blood vessels to the median and left lobe were clamped for 1 h and then reperfusion was allowed. The indices used were serial venous blood levels of AST, ALT, calcium, and ATP determination in liver tissue. In SOD-treated animals (7,5000 U i.v.) a significant attenuation of the rise in enzyme levels was observed as well as the absence of the decrease in calcium level in the early phase after reperfusion as compared with control rats, and furthermore ATP restoration was significantly increased.