Antagonistic effect of aminoguanidine on diabitic myocardial damage in rats

AIM:To investigate the mechanism of the antagonistic effect of aminoguanidine (AG) on diabitic myocardial damage in rats. METHODS:Morphology of myocardium in diabetic group and AG group were observed under transmission electron microscope (TEM). Activity of superoxide dismutase (SOD), nitric oxide synthase (NOS), inducible nitric oxide synthase (iNOS) and contents of malondialdehyde (MDA) were detected biochemically in myocardial homogenate. Nitrotyrosine (NT), which is the sign of peroxynitrite anion (ONOO^-), was detected using Western blotting. RESULTS:Under TEM, there was edema around nucleus of cadiocytes, part of inocommaes were breaked and Z lines were ambiguity, and part of costulaes and membranes of mitochondrion in cadiocytes were breaked or disappeared. The activity of NOS, iNOS and the content of MDA and NT increased in diabetic group as compared to control. The pathological changes of myocardium induced by diabetes were reversed in AG group, only part of costulaes of mitochondrion of cadiocytes disappeared, inocommaes were in order on the whole and only some lipid droplets deposited. The activity of NOS, iNOS and the content of MDA and NT in AG group decreased as compared to diabetic group. CONCLUSION:The protective effect of AG on diabitic myocardium may be through anti-lipid peroxidation and decreasing the content of ONOO^-.     

Protective effect of Ginkgo biloba extract on testicular tissue of diabetic rats

AIM: To investigate the protective effect of Ginkgo biloba extract (GBE) on diabetic testis and explore its possible mechanism. METHODS: Testicular structure of streptozotocin-induced diabetic rats was observed under light microscopy (LM) and transmission electron microscopy (TEM). Content of malondialdehyde (MDA), NO₂^-/NO₃^- and activity of superoxide dismutase (SOD), nitric oxide synthase (NOS) were determined in testicular homogenate. RESULTS: In diabetic rats, it was manifestated as deformation of seminiferous tubule, atrophy and shedding of germinal epithelium under LM, while expansion of smooth endoplasmic reticulum, formation of fatty vacuoles and decrease of lysosome obviously in the cytoplasm of sertoli cell under TEM, the injury of testicular tissue was improved by GBE. Compared with diabetic rats, activity of SOD increased while activity of tNOS and iNOS, content of MDA and NO₂^-/NO₃^- decreased in GBE-treated rats. CONCLUSION: GBE could effectively prevent the development of diabetic testis and the effect may be partly achieved by resisting lipid peroxidation,restraining the activity of testicular tissue iNOS and reducing the pathological alterations of NO.     

Oxygen free radical injury of myocardial mitochondria in the experimental type 2 diabetic rats

AIM: To study the mechanism of diabetic cardiomyopathy and abnormality of oxygen free radicals. METHODS: The contents of myocardial cytosolic cytochrome C, mitochondria cytochrome C, mitochondrial calcium, NO, MDA and the activity of SOD and NOS were determined in diabetic rats induced by STZ. The pathological changes were observed under transmission electron microscope. RESULTS: Compared to the normal and ganoderma group, the levels of mitochondrial NO, iNOS, MDA, calcium and plasma Cyt-C in rat myocardium were higher (P<0.05), while mitochondrial Cyt-C and SOD were lowered in model group (P<0.05). The bouncary indistinct, disorganization, a focal loss of muscular fibril, myocardium mitochondria swelling, pulmonary vascular endothelial cellular swelling and obstructed lumen of the capillary were also observed under transmission electronic microscope. CONCLUSION: The findings indicate that oxyradical and lipid peroxidation might be associated with the damage of myocardial mitochondria in NIDDM rats. Cyt-C and mitochondrial calcium is also involved in the process.     

Protective effects of extract of Ginkgo biloba on diaphragm of diabetic rats

AIM: To investigate the effects of extract of Ginkgo biloba (EGb) on diaphragm from diabetic rats. METHODS: Sprague-Dauley rats were divided into three groups: normal control, diabetic group and EGb treatment group. The morphologic changes of diaphragm tissues were studied by light and electron microscopy, the activities of succinate dehydrogenase (SDH), superoxide dismutase (SOD), nitric oxide synthase (NOS) and contents of malondialdehyde (MDA), nitric oxide (NO₂^-/NO₃-) in the diaphragm mitochondria were assayed by spectophotometer, respectively. RESULTS: The activities of SOD, SDH decreased in diabetic diaphragm mitochondria, but the activitiy of NOS, the contents of NO₂^-/NO₃^-, MDA increased compared with control group. The activities of SOD, SDH were increased as well as NOS were decreased and the contents of NO₂^-/NO₃^-, MDA decreased in EGb treatment group compared with the diabetic group. CONCLUSION: EGb may protects the diaphragm mitochondria of diabetic rats by enhancing the function of respiratory chain, anti-oxidation and decreasing NO level.     

Effect of gingko biloba extract on liver from experimental type 2 diabetic rats

AIM:To study the protective effect of the ginkgo biloba (EGB) extract on liver from experimental type 2 diabetic rats and to explore its possible mechanism. METHODS:Thirty-nine male Sprague-Dawley rats were divided randomly into four groups: normal control group, high-fat group, diabetic group and EGB-treated group. After fed with high-fat diet for 4 weeks, the later two groups were injected with streptozotocin intraperitoneally to induce type 2 diabetes mellitus. EGB-treated group was injected intraperitoneally with EGB at a dose of 8 mg·kg^-1·d^-1, and the other three groups were treated with normal saline of the same volume. After 8 weeks, the morphologic change of hepatic tissue was observed under transmission electron microscope (TEM) and light microscope (LM), respectively. In addition, the activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-PX), total nitric oxide synthase (TNOS), inducable nitric oxide synthase (iNOS) and the content of malondialdehyde (MDA), nitric oxide (NO) in liver homogenate were detected biochemically. RESULTS:Obvious liver fatty degeneration, apparent decrease of glycogen granules in cytoplasm of hepatocytes under light microscope and hepatocytes pyknosis, lots of lipid deposits in cytoplasm of hepatocytes, proliferation of hepatic stellate cells and collagen under TEM were observed in diabetic group. The activity of SOD, CAT, GSH-PX decreased but the activity of tNOS, iNOS and the content of MDA, NO^-₂/NO^-₃ increased in diabetic group compared with normal control group. The pathological change was relieved in EGB-treated group. The activity of SOD, CAT, GSH-PX increased, the activity of tNOS, iNOS and the content of MDA, NO^-₂/NO^-₃ decreased in the liver of rats in EGB-treated group compared with diabetic group. CONCLUSION:EGB exerts a beneficial effect on liver in experimental type 2 diabetic rats. Anti-lipid peroxidation and suppression of NO production may be involved in this process.     

Effects of cholecystokinin octapeptide on cerebral cortex injury during endotoxic shock

AIM: To study the effects of cholecystokinin octapeptide (CCK-8) on cerebral cortex injury during endotoxic shock (ES) and its mechanisms. METHODS: Rabbits were injected intravenously with lipopolysaccharide (LPS, 8 mg/kg) to establish ES model. Rabbits (n=32, 8 in each group) were randomly assigned to receive one of four treatments intravenously: normal saline (as control), LPS, CCK-8 pretreatment 30 min before LPS, proglumide (Pro, nonspecific antagonist of CCK receptors) pretreatment 30 min before LPS. The changes of mean arterial pressure (MAP) were measured. The morphologic changes in cerebral cortex were observed through light microscope (LM) and transmission electron microscope (TEM). The alterations of activities of nitric oxide synthase (NOS) and superoxide dismutase (SOD), contents of nitric oxide (NO) and malondialdehyde (MDA) in cerebral cortex were assayed. The expressions of protein of inducible NOS (iNOS) and neuronal NOS (nNOS) were detected by immunohistochemistry staining in cerebral cortex in 4 groups of Sprague-Dawley (SD) rats (n=12, 3 in each group) which were grouped as that of the rabbits. RESULTS: LPS administration resulted in lower MAP than that in control group (P<0.01). Hydropic degeneration of neurons and severe injuries to capillaries were observed in cerebral cortex of ES rabbits. LPS administration induced the expression of iNOS protein in the cytoplasm of neurocytes, and lead to stronger positive signals of nNOS than that in control group. NOS activity, NO2ˉ/NO3ˉ level and MDA content were higher (P<0.05, P<0.01 and P<0.01), while SOD activity was lower in cerebral cortex of ES rabbits than those in control group (P<0.01). CCK-8 pre-administration alleviated the changes induced by LPS, while Pro pre-administration aggravated those alterations. CONCLUSION: CCK-8 protects brain tissues against the injury induced by LPS, which may be associated with its effects of suppressing the overproduction of NO and free radicals.     

The relationship between nitric oxide and gastric mucosal injury induced by reserpine in rats

AIM: To study the relationship between nitric oxide (NO) and gastric mucosal injury induced by reserpine in rats. METHODS: Sixteen healthy male Wistar rats were randomly divided into control group and experimental group (n=8). NO contents and malondialdehyde(MDA) contents in plasma, gastric mucosa of the rats were respectively determined with Cadmium-reduct plus Greiss and TBA; nitric oxide synthase in gastric walls of the rats were observed using NADPH-diaphorase histochemistry and quantitatively measured with image analyzer. RESULTS: The NO contents in both plasma and gastric mucosa of experimental group were significantly lower than that in control group (P＜0.01),but their MDA contents were both higher than that in control group(P＜0.05,P＜0.01);the densities and A values of nitric oxide synthase (NOS)-positive nerve-cells and nerve fibers in gastric walls of experimental group were all obviously lower than that in control group (P＜0.05,P＜0.01). CONCLUSION: The mechanism of the reserpine-induced gastric mucosal injury in rats might be related to NO insufficiency arisen from the inhibition of NOS activity in NANC nerves in gastric wall,which might weaken the protection to gastric mucosa.     

Effect of altitude hypoxia on glutamate,aspartate and NOS in the rat hypothalamus

AIM: To investigate the effects of external counterpulsation (ECP) on nitric oxide (NO) and nitric oxide synthase (NOS) and the expression of NOS gene in myocardial infarction canines. METHODS: Nineteen healthy dogs were randomly divided into three groups ie. controls, ischemia group, ischemia and ECP group. Serum NO concentrations and myocardium NO levels and NOS specific activity were determined by modified nitrate reductase method. The protein synthesis of sub-type NOS including inducible NOS (iNOS) and endothelial NOS (eNOS) of myocardial tissue were also determined by immunohistochemical method. The constitutive NOS (cNOS) mRNA was measured via in situ hybridization. RESULTS: 120 and 180 minutes after the ligating of LAD, serum NO concentration in ECP groups were higher than those in ischemic groups (P＜0.05). The NO levels and NOS specific activity in myocardium of ischemic dogs were lower than those in controls and ECP group (P＜0.05). Protein synthesis of iNOS increased and that of eNOS decreased in ischemic myocardium. But ECP could control the protein synthesis of iNOS, and increase that of eNOS. Further studies showed that the expression of cNOS mRNA decreased in ischemic myocardial tissue, ECP might promote the expression of it and regulate NOS in the gene level. CONCLUSION: The results suggested that it was one of the most important mechanisms through raising the NO levels to protect ischemic myocardium in ECP.     

Renoprotective effects of sesamin on renal hypertensive and hyperlipidemic rats

AIM: To investigate the effects of sesamin on progression of renal injury in renal hypertensive and hyperlipidemic rats (RHHR). METHODS: RHHR was induced by 2K1C and high lipid baitvessel. After 7 weeks of intragastric administration with sesamin, the contents of serum creatinine (Scr), blood urea nitrogen (BUN), 24 h urinary protein excretion (UPE) were measured. In addition, the activity of total antioxidative capacity (T-AOC), superoxide dismutase (SOD), the concentrations of malondialdehyde (MDA), hydrogen peroxide (H2O2), and the nitric oxide synthase (NOS) and nitric oxide (NO) levels in renal homogenate were measured. RESULTS: Compared with the model group, seasamin (in 100 mg·kg-1 and 33 mg·kg-1 groups) evidently decreased the contents of Scr, BUN, UP and the concentration of MDA, iNOS, H2O2 in renal tissure. It also improved the levels of NO, cNOS and activity of SOD, T-AOC in renal tissure. CONCLUSION: Sesamin ameliorates hypertensive and hyperlipidemic-induced renal injury, probably by enhancing antioxidative activity, scavenging hydroxyl radical and restraining iNOS level.     

Liver protection by Sini decoction in hemorrhagic shock and its mechanism relating to oxygen free radical and nitric oxide

AIM:The work was designed to explore protective effects of a traditional Chinese medicine-sini decoction (SD) on liver in hemorrhagic shock and its mechanism relating to oxygen free radical and nitric oxide.METHODS:Anesthetized Wistar rats were subjected to a hemorrhagic shock protocol for 60 min followed by intravenous injection with normal sodium chloride solution or SD solution. Superoxide dismutase (SOD), malondialdehyde (MDA) and nitric oxide (NO) in liver were examined. The inducible nitric oxide synthase (iNOS) was determined immunohistochemically. RT-polymerase chain reaction (RT-PCR)was used to assay the mRNA, which were corresponding to eNOS (endothelial nitric oxide synthase) and iNOS.RESULTS:The activity of SOD decreased, while the concentration of MDA increased in liver during hemorrhagic shock. SD enhanced SOD activity and inhibited a increase in MDA level in liver (P＜0.01). The NO concentrations in liver in SD group increased at three hours after resuscitation (P<0.01). In addition, it was found that the expression of iNOS was upregulated in sodium chloride-treated group, while SD upregulated the expression of eNOS.CONCLUSION:SD reduces the liver injury caused by oxygen free radicals during hemorrhagic shock. The increasing NO concentration by SD is through upregulation of endothelial NOS expression.     

Effect of NG-nitro-L-arginine on mitochondria in acute lung injury induced by LPS in rats

AIM: To examine the effect of nonselective nitric oxide synthase inhibitor, NG-nitro-L-arginine (L-NA), on mitochondria from acute lung injury induced by lipopolysaccharides(LPS) in rats. METHODS: The rats were randomly divided into control group, LPS injury group and L-NA treatment group. The model of acute lung injury was prepared with injection of LPS in rats. L-NA was respectively administrated through intraperitoneal injection at 3 h after injury induced by LPS. The rats were killed and the mitochondria in lung tissues were isolated by differential centrifugation. The activities of T-NOS, iNOS, ATPase, SOD and GSH-Px, and the contents of NO and MDA from mitochondria were respectively measured. The changes of ultrastructure in lung mitochondria were examined by electronic microscope after injury and L-NA treatment. RESULTS: The activities of T-NOS and iNOS were significantly increased, the activities of ATPase, SOD and GSH-Px were significantly decreased, the contents of NO and MDA were increased after acute lung injury. L-NA significantly enhanced the activities of ATPase, SOD and GSH-Px, and markedly decreased the contents of NO and MDA and the activities of T-NOS and iNOS. CONCLUSION: L-NA inhibits the activity of NOS in mitochondria, decreases the production of NO, improves mitochondria energy pump, ameliorates oxidative injury, and effectively protects lung tissue against acute lung injury induced by LPS.     

Protective effects of total saponins of panax notoginseng on myocardial hypertrophy and fibrosis induced by isoproterenol in rats

AIM: To investigate the protective effects of total saponins of panax notoginseng (PNS) on myocardial hypertrophy and fibrosis induced by isoproterenol (ISO) in rats.METHODS: Myocardial hypertrophy and fibrosis model of rats were induced by injection of ISO (5 mg·kg^-1·d^-1,sc) for 7 days.From day 2,the rats were administered with PNS at dose of 25 and 50 mg·kg^-1·d^-1,ip for 14 days,the control and ISO model group were received saline injection.Then,the heart-weight (HW),left ventricular weight (LVW),the ratio of HW/BW and LVW/BW (LVI) were measured;the hydroxyproline and malondialdehyde (MDA) and angiotensin (AngII) content of left ventricle.The level of nitric oxide (NO),nitric oxide synthase (NOS),superoxide disrnutase (SOD) and glutathione peroxidase (GSH-Px) activities in left ventricle were determined by spectrophotemetry and radioimmunoassay,respectively.RESULTS: Compared with NS control group,the ratio of HW/BW,LVW/BW and the content of hydroxyproline,AngII,MDA and iNOS activity in the left ventricle were significantly increased.The cNOS,SOD,GSH-Px activities and NO content were obriously decreased in the ISO model group.After treatment with PNS,the left ventricular NO content,cNOS,SOD and GSH-Px activities were markedly higher than those in ISO model group.The content of MDA,AngII and iNOS activities and the ratio of HW/BW,LVI were significantly lower than those in ISO model group.CONCLUSION: PNS reverses the myocardial hypertrophy and fibrosis induced by isoproterenol in rats.This effect may be related to eliminating the oxygen free radicals and raising NO level.     

Glycine protection against the myocardial ischemic injury in mice

AIM:To observe the effect of glycine on the myocardial ischemic injury in mice. METHODS:Mice were supplied with 20% glycine twice daily (0.025 mL/g, ig), or 40% Injection salviae miltiorrhizae composita (ISMC, 0.025 mL/g, ig). One week later, 0.02 U/g pituitrin was injected intraperitoneally. The electrocardiogram was recorded, and activities of nitric oxide synthase (NOS), superoxide dismutase (SOD) and the content of malondiadehyde (MDA) in the myocardium were examined. RESULTS:Glycine reduced changes in J spot in electrocardiogram. Both glycine and ISMC increased activities of SOD and NOS, inhibited increase in MDA content in the myocardium induced by pituitrin. There was no difference in above parameters between glycine-treated and ISMC-treated mice. CONCLUSION:These results demonstrated that glycine can protect myocardium from ischemic injury, the mechanism may be related to increase in activities of NOS, SOD and supressing the lipid peroxidation.     

Role of endogenous nitric oxide synthase inhibitor in erectile dysfunction of diabetic rats

AIM: To investigate the role of nitric oxide synthase (NOS) inhibitor asymmetric dimethylarginine (ADMA) in erectile dysfunction of diabetic rats.METHODS: Type 2 diabetic rat model was established by 4 weeks of high-fat diet plus a single intraperitoneal injection of streptozotocin and continued high-fat diet feeding for 8 weeks. Corpus cavernosum was isolated from the rats under anesthetization, and the endothelium-dependent relaxation response to acetylcholine (ACh) was tested in an organ chamber to reflect erectile function. The level of ADMA in serum was detected. The NOS activity, nitric oxide (NO) content and cyclic guanosine monophosphate (cGMP) content in corpus cavernosum were measured. The protein expression of ADMA-NOS-NO pathway-related molecules and phosphodiesteras 5 (PDE5) in the corpus cavernosum was detected by Western blot. Superoxide dismutase activity and malondialdehyde content were analyzed to evaluate oxidative stress.RESULTS: Elevated blood glucose and lowered insulin sensitivity were observed in the diabe-tic rats, indicating that type 2 diabetic rat model was successfully established. Compared with control group, the relaxation response to ACh of corpus cavernosum from diabetic rats was significantly decreased, which was accompanied with the elevation of serum ADMA level and reduction of NOS activity, NO content and cGMP content in the corpus cavernosum. The protein expression of ADMA-generating enzyme protein arginine methyltransferase 1 was up-regulated, while ADMA-metabolic enzymes dimethylarginine dimethylaminohydrolases 1 and 2, and ADMA-targeting enzymes endothelial NOS and neuronal NOS were down-regulated. The protein expression of PDE5 was up-regulated, accompanied with an increase in oxidative stress in the corpus cavernosum of diabetic rats. Incubation of isolated corpus cavernosum from normal rats with NOS inhibitor ADMA induced the similar relaxation dysfunction of corpus cavernosum response to ACh and decreased NO and cGMP contents in diabetic rats.CONCLUSION: Elevated endogenous NOS inhibitor ADMA plays an important role in erectile dysfunction of diabetic rats. The underlying mechanism may be related to the reduction of NO production and the increase in oxidative stress.     

Effects of external counterpulsation on nitric oxide system in myocardial infarction canines

AIM:To investigate the effects of external counterpulsation(ECP)on nitric oxide(NO)and nitric oxide synthase(NOS)and the expression of NOS gene in myocardial infarction canines.METHODS:Nineteen healthy dogs were randomly divided into three groups ie.controls, ischemia group, ischemia and ECP group.Serum NO concentrations and myocardium NO levels and NOS specific activity were determined by modified nitrate reductase method.T he protein synthesis of sub-type NOS including inducible NOS(iNOS)and endothelial NOS(eNOS)of myocardial tissue were also determined by immunohistochemical method.The constitutive NOS(cNOS)mRNA was measured via in situ hybridization.RESULTS:120 and 180 minutes after the ligat ing of LAD, serum NO concentration in ECP groups were higher than those in ischemic groups(P<0.05).The NO levels and NOS specific activity in myocardium of ischemic dogs were lower than those in controls and ECP group(P<0.05).Protein synthesis of iNOS increased and that of eNOS decreased in ischemic myocardium.But ECP could control the protein synthesis of iNOS, and increase that of eNOS.Further studies showed that the expression of cNOS mRNA decreased in ischemic myocardial tissue, ECP might promote the expression of it and regulate NOS in the gene level.CONCLUSION:The results suggested that it was one of the most important mechanisms through raising the NO levels to protect ischemic myocardium in ECP.     

Effects of hyperbaric oxygen and cyclosporin A on thelevels of active oxygens and nitric oxide in spleens of skin transplanted mice

AIM: To study effects of hyperbaric oxygen (HBO) and cyclosporin A (CsA) on the contents of active oxygens and nitric oxide (NO) in spleens of skin transplanted mice. METHODS: The donor mice BALB/C and receptor mice C₅₇BL/6 were tested for skin transplantation. The HBO group mice were treated with 99.2% oxygen under 0.25 MPa for 1.5 hours, while CsA group mice were treated with CsA 0.5 mg·kg^-1·d^-1 by abdomen injection. After 14 days, the spleen were extracted the contents of malondialdehyde (MDA) and NO and the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), catalase (CAT) and NO synthases (NOS) were determined. RESULTS: (1) Compared with the control group, the transplantation group, HBO group and CsA group have markedly increased the content of MDA and the activities of GSH-PX and CAT; Compared with the transplantation group, the CsA group have markedly increased activity of SOD and reduced activities of GSH-PX and CAT; the HBO group have markedly reduced the activity of GSH-PX and increased the activities of CAT and SOD (P<0.01). (2) Compared with the control group, the transplantation group have markedly increased the content of NO and the activity of NOS; Compared with the transplantation group, the HBO group have markedly increased the activity of NOS and reduced the content of NO (P<0.01); The content of NO and the activity of NOS in CsA group was not changed significantly. CONCLUSION: In the lymphocytes of the transplantation group, the peroxidation is intensified, and the content of NO and the activity of NOS increased. HBO and CsA may activate the systems of oxidation/antioxidation and NO/NOS in spleen, which may be related to their mechanism of inhibition rejection.     

Effects of extract of gingko biloba on the lipid metabolism and the function of macrophages from diabetic rats

AIM: To study effect of extract of ginkgo biloba (EGb) on the lipid metabolism and the function of macrophages from diabetic rats.METHODS: Sprague-Dauley rats were divided into four groups: normal control group, high-fat group, diabetic group and EGb treatment group.At the end of experiment, the rats were sacrificed, the blood glucose, blood insulin and serum lipid were measured.The activity of superoxide dismutase (SOD), content of malondialdehyde (MDA), nitric oxide (NO) in alveolar macrophages (AM) and peritoneal macrophages (PM) were assayed.In addition, peroxisome proliferator activated receptor γ (PPARγ), CD36 mRNA expression in AM was measured by RT-PCR.RESULTS: The concentration of the blood glucose, blood insulin and total cholesterol (TC), total triglycerides (TG), low-density lipoprotein- cholesterol (LDL-C) in blood increased significantly in type 2 diabetic group.The supplement of EGb decreased blood glucose, blood insulin and TC, TG, LDL-C levels.The activity of SOD decreased, while the content of NO, MDA increased in the diabetic macrophages, the activity of SOD became increased, but the content of NO and MDA decreased in EGb-treated group.The mRNA expression level of CD36 and PPARγ in alveolar macrophages from diabetic group increased, while expression level of CD36 and PPARγ mRNA in EGb treated rats continued to rise.CONCLUSIONS: EGb corrected insulin resistance and ameliorated disturbance of lipid metabolism caused by type2 diabetes in rats.Adjustment of PPARγ and CD36 mRNA expression of as well as reduction of lipid peroxidation and NO level may be involved in this process.     

Mechanism of mesenteric lymph duct ligation against the renal insufficiency in hemorrhagic shock rats

AIM: To observe the effect of mesenteric lymph duct ligation on free radical and inflammatory mediator in serious hemorrhagic shock rats at different periods, and explore the mechanism of intestinal lymphatic pathway on renal insufficiency. METHODS: 78 male Wistar rats were divided into the sham group, shock group, and ligation group. The model of serious hemorrhagic shock was established in shock group, ligation group, and mesenteric lymph was blocked by ligating mesenteric lymph duct in ligation group after resuscitating. All rats were executed and kidneys were taken out for making homogenate of 10 percent to determine levels of MDA, SOD, NO, NOS, tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and myeloperoxidase (MPO) at time points after shock 90 min, after transfusion and resuscitate 0 h, 1 h, 3 h, 6 h, 12 h and 24 h. The expression of inducible nitric oxide synthase (iNOS) mRNA in kindey was detected by RT-PCR. RESULTS: The contents of MDA, NO, NOS, TNF-α, IL-6, MPO and iNOS expressions in renal homogenate of shock group were increased after transfusion and resuscitation, and were higher at 6 h and 12 h, and was significantly higher than that in sham group. The acvitity of SOD was significantly lower than that in sham group (P<0.01, P<0.05). The contents of MDA, NO, NOS, TNF-α, IL-6, MPO and iNOS expression in renal homogenate of ligation group after transfusion and resuscitation 6 h, 12 h and 24 h were significantly lower than those in shock group at same points, and the SOD activity was higher (P<0.01, P<0.05). CONCLUSION: The results demonstrate that the ligation of mesenteric lymph duct can antagonise the development of renal failure in serious hemorrhagic shock rats, and its mechanism might relate to reduce the PMN sequestration, decrease the levels of TNF-α and IL-6, inhibit NO production and expression of iNOS mRNA, suppress the release of free radical and consumption of SOD.     

Changes of free radicals and antioxidative system of prostate tissue in the male rats with short-term diabetes

AIM:To study the dynamic changes of free radicals and antioxidative system of prostate in rats with short-term diabetes.METHODS:48 Wistar male rats were divided into 6 groups at random (8 rats in each group). One group were injected(ip) with sodium citrate buffer to be the control group, the other 5 groups were injected (ip) with steptozocin(STZ) 60mg/kg body weight which were called diabetes group. Rats were killed after 1, 3, 5, 7 and 14 days; superoxide dismutase(SOD), malondialdehyde(MDA), glutathione(GST), glutathione s-transferase(GST), glutathione peroxidase(GSH-px), nitric oxide (NO) and nitric oxide synthase(NOS) of prostate were examined.RESULTS:The levels of MDA, GSH-px and NO in prostate homogenate of diabetes group were higher evidently as compared with control levels. The activities of SOD, GST, NOS and the levels of GSH in prostate homogenate were increased obviously after injection of STZ with control levels, then returned near to control values.CONCLUSION:The evidences mentioned above indicate that high-level of free radicals and decrease in antioxidative system rendere the prostate cells to be in oxidative stress.