Effects of different doses of L-dopa on rotational behavior and amounts of cells expressing D2 receptors in hemiparkinsonian rats

AIM：To observe the effects of different doses of L-dopa on the rotational behavior and amounts of cells expressing D₂ receptors in striatum in hemiparkinsonian rats.METHODS：A hemiparkinsonian model was established in rats by pretreatment with 6-hydroxydopamine.The D₂ receptor expression were detected by immunohistochemical staining.The numbers of rotations induced by apomorphine was counted within 30 min before and after L-dopa (10 mg·kg^-1·d^-1,50 mg·kg^-1·d-^-1 or 100 mg·kg^-1·d^-1,ip) was introduced to Parkinson’s disease (PD) model rats for 15 days.RESULTS：In successful PD model rats,the increased percentage of D₂ receptor in lesioned side compared with intact side was associated linearly with the numbers of rotations within 30 min (r=0.927,P<0.01).After high dose of L-dopa intervention to PD model,the numbers of rotations decreased significantly (P<0.05),the amounts of cells expressing D₂ receptor at the lesioned side striatum decreased significantly (P<0.01).CONCLUSION：After high dose of L-dopa intervention,rotation behavior of PD rats improves,and D₂ receptor is down-regulated significantly.     

Astragali radix extract ameliorates renal resistance to atrial natriuretic peptide in rats with experimental nephrotic syndrome

AIM: To study the effects of astragali radix extract (ARE) on renal resistance to atrial natriuretic peptide (ANP) in rats with experimental nephrotic syndrome. METHODS: Male Sprague-Dawley rats were randomly divided into normal control, adriamycin nephropathy (ADR), ADR treated with ARE (2.5 g· kg^-1· d^-1) and ADR treated with benazepril (10 mg· kg^-1· d^-1). After 6 weeks, rats received intravenous infusion of 2% body weight isotonic saline. Urinary cGMP excretion (U_cGMPV), plasma ANP level, renal PDE5 activity and protein expression were also detected. RESULTS: ARE increased U_NaV while ACEI was not natriuretic. Nephrotic rats had a blunted natriuretic response and reduced rate of U_cGMPV after volume expansion despite higher plasma ANP concentration. ARE increased U_cGMPV and restored partly natriuretic response to volume expansion. The activity and protein abundance of renal PDE5 were high in nephrotic rats. ARE significantly reduced the PDE5 activity and protein expression. CONCLUSION: ARE may ameliorate the renal resistance to ANP in rats with adriamycin nephropathy by inhibiting the PDE5.     

Effects of angiotensionⅡon metalloproteinases and matrix in hypertrophied myocardium from infarcted rats

AIM: To investigate the roles of angiotensionⅡ (AngⅡ) receptors (AT₁, AT₂) antagonists on matrix metalloproteinases (MMPs) and extracellular matrix (ECM) system in septal myocardium from infarcted rats.METHODS: The model of rat myocardium infarction (MI) was established by permanent ligation of the left coronary artery. The treatments of the AT₁ receptor antagonist valsartan (10 mg·kg^-1·d^-1) or AT₂ receptor antagonist PD123319 (30 mg·kg^-1·d^-1) were started 7 days prior to surgery. On day 14 after MI, protein levels of MMP-2, 3, 9, fibronectin (FN), tenascin-C (TN-C) in interventricular septum (IS) were determined. The distributions of FN and TN-C were also determined by immunofluorescence.RESULTS: Pathological changes of IS on day 14 after MI showed typical myocardial hypertrophy. Protein expressions of MMP-2, 3, 9 and TN-C of IS in banding group were higher than those in sham-operation group (P<0.01). The expressions of TIMP-1 and FN were lower than those in sham-operation group (P<0.01). Protein expressions of MMP-2, 3, 9 and TN-C in valsartan group were obviously lower than those in banding and PD123319 groups (P<0.01). TIMP-1 and FN protein expressions in valsartan group were higher than those in banding and PD123319 groups (P<0.01). No difference between banding and PD123319 groups was observed (P>0.05).CONCLUSION: AngⅡis involved in myocardium remodeling in infarcted rats, which is mediated via AT₁ receptor to degrade matrix by MMPs. The heart protection of AT₁ receptor antagonists may relate to inhibition of MMPs.     

Rifampicin protects rats against rotenone-induced dopaminergic neurons damage

AIM:To investigate the protective effect of rifampicin on rotenone-induced apoptosis of dopaminergic neurons and expression of α-synuclein in rats. METHODS:Highly selective lesions and high expression of α-synuclein in nigrostriatal dopaminergic neurons in rats were induced by chronic subcutaneous exposure to rotenone at dose of 1.5 mg·kg^-1·d^-1 for 3 weeks. At the same time, rifampicin was administered at dose of 30 mg·kg^-1·d^-1 by intragastric administration for 3 weeks. The changes of behavior, pathology and immunoreactivity of TH and α-synuclein in SNc were observed. RESULTS:Obvious changes of behavior, pathology and TH immunoreactivity in SNc were observed in male SD rats injected subcutaneously with rotenone and rifampicin protected rats against these toxic effects induced by rotenone. CONCLUSION:Rifampicin has extensive protective effects against rotenone-induced neurotoxicity, which is related to inhibiting the expression and aggregation of α-synuclein.     

Effect of pioglitazone on glucose metabolism and PPAR-γ expression in lipid-infused rats

AIM: To investigate the effect of pioglitazone (Pio) on glucose metabolism and peroxisome proliferators-activated receptor (PPAR)-γ expression in free fatty acid (FFA) -induced insulin resistance in rats. METHODS: A hyperinsulinaemic-euglycaemic clamp and ［3-3H］-glucose tracing technique were used in awake rats. Glucose metabolism in vivo and PPAR-γ in adipose tissue expression were assessed with elevation FFA by lipid infusion over 4 h in rats pretreated with or without Pio.RESULTS: During steady-state of clamp, there was a significant increase in plasma FFA in two lipid-infused groups, compared to control rats (P<0.01). The glucose infusion rates (GIR) in Pio-treated rats (P/L group), compared with controls, were significantly reduced ［(20.6±0.4) mg·kg^-1·min^-1 vs (33.6±0.6)mg·kg^-1· min^-1, P<0.01］, whereas the GIR was lower in the lipid group (L group) than that in the P/L group［(12.6±0.8) mg·kg^-1·min^-1 vs (20.6±0.4) mg·kg^-1·min^-1, P<0.01］. The hepatic glucose production (HGP) was significantly suppressed (85%) ［(18.3±2.1)mg· kg^-1·min^-1 (basal) vs (2.7±2.4)mg· kg^-1·min^-1, and (17.5±2.6) mg· kg^-1·min^-1 vs (2.6±1.0)mg· kg^-1·min^-1］, all P<0.01 during clamp in control and P/L groups. The suppressive effect of insulin on HGP was significantly blunted in L group［(17.3±2.1)mg· kg^-1·min^-1 vs (15.8±1.5)mg· kg^-1·min^-1］. The rate of glucose disappearance (GRd) was significantly reduced in two lipid-infused rats compared with controls［(26.6±1.6)mg· kg^-1·min^-1 and (23.2±0.9)mg· kg^-1·min^-1 vs (37.7±2.6)mg·kg^-1·min^-1,P<0.01］. The PPAR-γ expression of adipose tissue in P/L group was significantly upregulated. CONCLUSION: Lipid-infusion induces an acute insulin-resistance in vivo. Pio treatment upregulates the PPAR-γ of adipose tissue and suppresses HGP. Pio can protect partly against lipid-induced insulin resistance.     

Effects of atorvastatin on the experimental autoimmune myocarditis in Lewis rats

AIM:To test the hypothesis that atorvastatin affects T cell-mediated autoimmunity through modulating the balance of Th1/Th2 and reduces the severity of EAM. METHODS:Myocarditis was induced in Lewis rats by injection of porcine cardiac myosin. High-dose (10 mg·kg^-1·d^-1) or low-dose (1 mg·kg^-1·d^-1) atorvastatin or vehicle was administered orally for 3 weeks. On day 21, echocardiography was examined and the severity of myocarditis was detected by histopathological evaluation. Levels of serum IFN-γ, IL-2, IL-4 and IL-10 were measured by ELISA. RESULTS:Cardiac function and histological severity of myocarditis were improved in the two atorvastatin-treated groups. Treatment with atorvastatin decreased the levels of Th1 cytokine (IFN-γ, IL-2) and increased the levels of Th2 cytokine (IL-4, IL-10). CONCLUSION:These results suggest that HMG-CoA reductase blockade may be a promising new strategy for the treatment of autoimmune myocarditis.     

Effect of atorvastatin on ventricular remodeling in spontaneous hypertension rats

AIM：To explore the effect of atorvastatin on cardiac remodeling in spontaneous hypertension rats (SHR).METHODS：Twelve spontaneous hypertension rats were divided randomly into two groups：group of atorvastatin (atorvastatin 50 mg·kg^-1·d^-1) and group of SHR (0.5% mucilage of arabic gum,10 mL·kg^-1·d^-1).Additionally,six male Wistar-Kyoto rats (0.5% mucilage of arabic gum,10 mL·kg^-1·d^-1) were selected as control group.Systolic blood pressure was assessed with the tail-cuff method.After six weeks,entire heart,and left ventricle were weighed.The left ventricular weight index was calculated and myocardial hydroxyproline and collagen protein concentration were measured.The serum high sensitivity CRP (hs-CRP) was measured by nephelometry.The localization of vascular cell adhesion molecule (VCAM) in myocardium was investigated by immunohistochemistry assays.The level of NF-κB mRNA expression was detected with in situ hybridization.Ultrastructure in cardiac muscle was also observed under transmission electron microscope.RESULTS：The expression of myocardial VCAM and NF-κB in SHR group was stronger than that in WHY group.Compared with SHR group,entire heart weight,left ventricular weight,left ventricular weight index,serum hs-CRP,myocardial hydroxyproline and collagen protein concentration was decreased,the expression of myocardial VCAM and NF-κB in SHR group was weaker than that in atorvastatin treatment group.The myocardial pathological change such as incomplete karyotheca in cardiac muscle cells,no clear of transverse striation and the mess in myofibril alignment,and hyperplasy in interstitial collagen fibre were observed in SHR group and these changes were improved in atorvastatin treatment group.CONCLUSION：The cardiac remodeling in SHR is improved by atorvastatin.The molecular mechanism may be related to its down-regulating the expression of VCAM protein and NF-κB and inhibiting myocardial chronic inflammation.     

Protective effects of tongxinluo,carvedilol and valsartan on microvascular endothelial function and integrity after late reperfused AMI in rabbits

AIM:To compare the protective effects of tongxinluo, a Chinese medicine, and carvedilol and valsartan on myocardium microvascular endothelial function and integrity after late reperfusion of acute myocardial infarction (AMI) in rabbits. METHODS:Forty-eight rabbits were randomly assigned to the following groups:(1) sham operated rabbits;(2) ischemia-reperfusion (I-R) controls;(3) tongxinluo (1.0 g·kg^-1·d^-1);(4) carvedilol (5 mg·kg^-1·d^-1);(5) valsartan (10 mg·kg^-1·d^-1) and (6) ticlopidine + aspirine (30 and 20 mg·kg^-1·d^-1, respectively) groups. After 3 d of drug treatment, the left coronary artery in the rabbit was ligated for 2 h and loosed subsequently for another 2 h. The serum levels of nitric oxide (NO₂^-/NO₃^-) and endothelin (ET) at baseline before AMI, 2 h after both AMI and reperfusion were examined. Also, the number of circulating endothelial cells (CEC), MI size and percentage myocardium focal bleeding incidence were determined 2 h after reperfusion. RESULTS:(1) The baseline level of NO₂^-/NO₃^- was significantly higher in tongxinluo group than that in other groups (all P<0.01), whereas the content of ET was not significantly different among the groups. 2 h after both AMI and reperfusion, NO₂^-/NO₃^- was significantly reduced (P<0.05, P<0.01) and ET was significantly increased in each group as compared with their baseline (P<0.05, P<0.01). Yet among the groups, NO₂^-/NO₃^- was still significantly higher and ET was significantly lower in tongxinluo-treated group than that in the other groups (P<0.05, P<0.01). (2) CEC number was significantly increased in I-R controls as compared with sham group (P<0.01), and was significantly reduced in the tongxinluo-treated groups as compared with I-R controls (P<0.05). (3) MI size was significantly reduced in the four treatment groups as compared with I-R controls (all P<0.01). (4) The percentage of myocardium focal bleeding incidence was significantly lower in tongxinluo and valsartan-treated groups than that in I-R controls (P<0.05, P<0.01). CONCLUSION:Tongxinluo as well as valsartan effectively protectsmyocardium endothelial function and integrity during AMI and late reperfusion,with the effects of tongxinluo being superior.     

Porcine surfactant in treatment of LPS-induced early-stage acute lung injury in rats

AIM: To evaluate the therapeutic efficacy of intratracheal instillation of porcine pulmonary surfactant (PPS) in rats with lipopolysaccharides (LPS)-induced early-stage ALI in this study.METHODS: SD rats weighing 200 g-300 g were randomly divided into 4 groups: LPS (1.5 mg·kg-1)+saline,LPS+PPS 100 mg·kg^-1,LPS+PPS 150 mg·kg^-1,LPS+PPS 200 mg·kg^-1.The PaO₂ and PaCO₂,as well as survival rate of rats were examined for 6 h after the start of PPS-instillation.Then,rats were killed and lungs were immediately removed for lung index (LI) and histological analysis.The bronchoalveolar lavage fluid (BALF) was collected for measurement of total protein (TP) contents,TNF-α level and white blood cell(WBC) numbers.RESULTS: Significantly increased PaO₂,reduced mortality rate,decreased total protein and TNF-α contents in BAL,as well as lung index and meliorated histological appearance were observed in three PPS-treated groups compared with group given saline after LPS (P<0.05).The therapeutic effect in PPS150 and PPS200 groups was better than that in PPS100 group.CONCLUSION: Intratracheal PPS instillation provides protective effect on acute lung injury in rats induced by LPS.     

Therapeutic effect of sodium arsenite on rheumatoid arthritis in rats

AIM:To study the molecular mechanism of rheumatoid arthritis (RA) and the effects of sodium arsenite on AP-1 and MIP-1. METHODS:32 Wistar female rats were randomly divided into 4 groups: normal control (C), arthritis (A), low concentration of sodium arsenite (LSA) and high concentration of sodium arsenite group (HSA).The LSA group and the HSA group were treated with sodium arsenite (0.5 mg·kg^-1·d^-1 and 1.0 mg·kg^-1·d^-1) through abdominal cavity injection for 20 days. The normal control group and the model group were treated with saline (0.2 mL/d). The AP-1 and MIP-1α expression of synovium in four groups were determined by immunohistochemistry. Light microscope was used to observe the synovium with HE staining. RESULTS:Compared with C group, the expression of AP-1 and MIP-1α in the synovium up-regulated in A group (P<0.01) and were inhibited by sodium arsenite treatment (P<0.05), especially in HSA group. CONCLUSION:The activated AP-1 and MIP-1α play an important role in the development of rheumatoid arthritis. Sodium arsenite down-regulated the expression of AP-1 and MIP-1α and may have some therapeutic effects in RA.     

Influence of Weimaining on the cell cycle of murine Lewis lung carcinoma

AIM:To investigate the anti-tumor effect of Weimaining (WMN) on a murine Lewis lung carcinoma (3LL) and the influence on the cell cycle. METHODS:The inhibitory rate of WMN in 3LL growth was detected by replicating the model of 3LL. The effect of the drug on 3LL cell cycle and the influence of the drug on the expression of cyclin D1 protein were investigated by flow cytometry and immunohistochemical staining. RESULTS:The results showed that the inhibitory rate of drug in 3LL is 19.14%, 33.59%, 40.63% and 51.56% respectively at dosage ranging from 100,150, 200 and 250 mg·kg^-1·d^-1. The drug inhibits tumor growth in a dose-dependent manner. The drug arrests 3LL cells in G₀-G₁ phase and decreases the expression of cyclin D1 protein. CONCLUSION:WMN inhibits the growth of 3LL cells in vivo by decreasing the expression of cyclin D1, blocking the cells in G₀-G₁ phase and preventing the cells transition from G₁ to S phase while DNA is replicated.     

Effects of DEHP on testosterone synthesis in fetal Leydig cells of newborn male rats

AIM: To observe the effects of diethylhexylphthalate(DEHP) on testosterone synthesis in fetal Leydig cells(FLC) of newborn male rats.METHODS: The pregnant rats were exposed to DEHP at dose of 10 mg·kg^-1·d^-1, 100 mg·kg^-1·d^-1 or 750 mg·kg^-1·d^-1(body weight) by gavage from gestation 12 days(GD 12) to postnatal 1 day(PND 1) respectively. The serum level of testosterone was detected by chemiluminescence. The morphology of FLC from the testes was observed under light microscope and transmission electron microscope. The mRNA expression of steroidogenic acute regulatory protein(StAR) and insulin-like growth factor I(IGF-I) was detected by real-time PCR(ΔΔCT). RESULTS: The serum testosterone level in low dose group was significantly higher than that in control, middle and high dose groups. The serum testosterone level in middle and high dose groups was significantly lower than that in control group(P<0.05). Light microscopy showed the aggregative cluster distribution of FLCs in low dose group, while manifested as tumor-like hyperplasia of FLCs in middile dose group and high dose group. Under electron microscope, the FLC in low dose group showed oval-shape or long spindle-shape, the lipid particles were decreased, but smooth endoplasmic reticulum and mitochondria were increased in cytoplasm. In middle and high dose group, the FLC were spindle or oval-shaped, showed large or small, nuclear large, round, rich in cytoplasm and cell aggregation, the cytoplasm was rich lipid particles with deep-stained, smooth endoplasmic reticulum and mitochondria were expanded. Compared to control group, the mRNA expression of StAR in low, middle and high dose group was decreased. The mRNA expression of StAR in high dose group was decreased more significantly(P<0.01) as compared to that in control group, while the mRNA expression of IGF-I in low dose group and middle dose group was increased, but that only in low dose group was increased more significantly as compared to control group(P<0.01). CONCLUSION: DEHP has toxic effect on FLC and changes the morphology and steroidogenic capacity in testicular FLC. The low dose of DEHP elevates the gene expression of IGF-I, and IGF-I stimulates the production of testosterone by FLC. The high dose of DEHP may inhibit the gene expression of StAR to reduce the serum levels of testosterone.     

Effects of thalidomide on the expression of NF-κB and TNF-α in experimental hepatic fibrotic rats

AIM: To study the effects of thalidomide on the expressions of nuclear factor κB (NF-κB) and tumor necrosis factor-α (TNF-α) in rat liver fibrosis.METHODS: The fibrosis of rat liver was induced by intraperitoneal injection of carbon tetrachloride thrice weekly.Meanwhile thalidomide (10 mg·kg^-1·d^-1 or 100 mg·kg^-1·d^-1) was given daily by the intragastric route for 8 weeks.Serum alanine aminotransferase (ALT),aspartate aminotransferase (AST),prealbumin (PA),hyaluronic acid (HA) and laminin (LN),and hydroxyproline (HYP) contents in the liver,NF-κB p65 and α-smooth muscle actin (α-SMA) protein in the liver,IκBα and TNF-α protein in cytoplasm and NF-κB p65 protein in nucleus and TNF-α mRNA levels in the liver were studied.RESULTS: Compared with the model group,the Knodell score,serum ALT,AST,HA,LN levels and HYP contents in liver,NF-κB p65 protein in nucleus and α-SMA protein in the liver,and TNF-α mRNA and protein in the liver of rats given high dose of thalidomide were decreased significantly (P<0.01).Meanwhile PA level and IκBα protein in cytoplasm were elevated significantly (P<0.01).CONCLUSION: Thalidomide exerts its effect on the down-regulation of NF-κB-induced TNF-α via inhibiting dissociation and degradation of IκB and prevents liver fibrosis in rats.     

Preventive effect of 3,4-dihydroxyacetophenone on atherosclerosis and role of visfatin expression

AIM: To observe the preventive effect of 3,4-dihydroxyacetophenone (DHAP) on atherosclerosis (AS) and the role of visfatin expression in ApoE(-/-) mice.METHODS: Eight-week-old normal mice were used in normal control group (n=8). Eight-week-old male ApoE (-/-) mice were randomly divided into 3 groups: AS group (n= 8, im. NS), DHAP treatment group (n=8, im. DHAP 10 mg·kg^-1·d^-1) and simvastatin treatment group (n=8, im. simvastatin 10 mg·kg^-1·d^-1). All mice were fed with Western diet (21% fat, 0.15% cholesterol) for 12 weeks. The blood samples were collected and the concentrations of blood lipids and visfatin were detected. The frozen sections of aortic root were stained with oil red O. The visfatin in atherosclerotic plaques at aortic roots was examined by Western blotting. The structures of smooth muscle cells and endothelial cells were observed under electron microscope. RESULTS: In DHAP-treated mice, the concentrations of visfatin, TG and TC were decreased, the formation of AS plaque was reduced, the injuries of smooth muscle cells and endothelia cells were attenuated. Visfatin was also decreased at atherosclerosis plaque in DHAP-treated mice.CONCLUSION: DHAP effectively prevents and treats AS by inhibiting the production of visfatin and reducing lipid.     

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.     

Effect of angelica on myocardial fibrosis post myocardial infarction in rats

AIM: To investigate 1) the role of transforming growth factor-β₁ (TGF-β₁) and macrophage infiltration during the development of myocardial fibrosis (MF) in rats after myocardial infarction (MI);and 2) mechanisms of MF post-MI and the inhibitory effect of angelica.METHODS: Sprague-Dawley (SD) rats were subjected to MI by ligating the left anterior descending coronary artery.The animals were randomly divided into three groups: sham, MI and MI+angelica.After 24 hours of ligation, rats received angelica (20 mL·kg^-1·d^-1, ip) or saline.Left ventricular hemodynamics were measured and rats were killed at week 1, week 2 and week 4, respectively.Collagen content, macrophage infiltration and TGF-β₁ expression were examined in the non-infarcted area.RESULTS: ① In MI group, the numbers of macrophage and TGF-β₁ expression were significantly upregulated compared to sham at week 1 post-MI and remained elevated at week 4 (P<0.01).Angelica significantly decreased macrophage infiltration and TGF-β₁ expression (P<0.01 vs MI).② Collagen content was increased significantly in MI group compared to sham at week 2 and week 4 (P<0.01), and decreased in MI+angelica group (P<0.05 vs MI).③ Cardiac function was markedly decreased post-MI in MI group (P<0.01), and improved at week 4 in MI+angelica group (P<0.05).CONCLUSION: In MF post-MI, angelica may have an antifibrotic effect by decreasing macrophage infiltration and TGF-β₁ expression, by which reactive myocardial fibrosis is reduced, and cardiac function is improved.     

Influences of Vit-E on the mtDNA damage and Ca2+ homostasis of hippocampus and antioxidative ability in brain of aging mice induced by D-galactose

AIM: To study the influences of vitamin E (Vit-E) on the mtDNA damage and Ca²⁺ homeostasis in hippocampus and antioxidative ability in aging brain induced by D-galactose.METHODS: D-galactose (1 000 mg·k^-1·d^-1 ) was injected into mice hypodermically for 8 weeks to induce aging animal model, and Vit-E (100 mg·kg^-1; 250 mg·kg^-1) was administered for 6 weeks by ig at the 3rd week of making model. After Vit-E treatment for 8 weeks, water maze test was used to determine the ability of mice’s learning and memory. The activities of glutathione peroxidase (GSH-Px) and succinate dehydrogenase (SDH), the content of nitric oxide (NO) and activity of nitric oxide synthase (NOS) in the brain tissue were detected separately. Fura-2/AM, double-wave-length fluorospectrophotometer and PCR method were used to measure the concentration of calcium ion and mtDNA mutation in the hippocampus cells.RESULTS: Administration of Vit-E improved significantly the ability of learning and memory in model mice, inhibited the activity of NOS and decreased the amount of NO, and increased the activities of GSH-Px and SDH respectively in brain tissues, decreased the concentration of calcium ion (P<0.01, P<0.05), and prevented the damage of mtDNA in hippocampus.CONCLUSION: Vit-E can enhance the antioxidative ability, regulate the homeostasis of Ca²⁺ and inhibit the damage of mtDNA caused by oxidative stress in aging brain, and improve the ability of learning and memory in aging mice.     

Intervention of Lipo-PGE1 on liver blood perfusion by different time and medication: a empirical study

AIM: To explore the effect and mechanism of liposome prostaglandin E₁(Lipo-PGE₁) on liver blood perfusion by different time and medication.METHODS: Twelve healthy adult dogs were injected with Lipo-PGE₁₁ μg/kg via left small saphenous vein at speed of 0.05 μg·kg^-1·min^-1.Liver computed tomography perfusion imaging (CTPI) was performed on 0,5,15 and 30 min,and the value of hepatic arterial perfusion (HAP),portal vein perfusion (PVP) and total liver perfusion (TLP) among groups were compared.The impacts of Lipo-PGE₁ on liver haemodynamics at different time were investigated.Twenty-four health dogs were randomly divided into four groups: control group,peripheral vein group,hepatic artery group and superior mesenteric artery group.Liver CTPI was performed at 5 min after 1 μg/kg Lipo-PGE₁ administration in those groups.The values of HAP,PVP and TLP were compared and effects of Lipo-PGE₁ on liver blood flow by different medication were observed.RESULTS: The values of liver perfusion (mL·min^-1·mL^-1) at 0,5,15 and 30 min after 1 μg/kg Lipo-PGE₁ administration via vein were as follows: HAP: 0.22 ±0.65,0.24±0.65,0.22±0.69,0.22±0.06;PVP: 1.22±0.40,1.88±0.59,1.55±0.55,1.29 ±0.57;TLP: 1.44±0.42,2.12±0.61,1.77±0.56,1.51±0.58,respectively.No significant difference in HAP among groups was observed,but in PVP and TLP,significant differences (F=3.812,P<0.05;F=3.805,P<0.05) among groups were found.The values of PVP and TLP were most obviously increased at 5 min,and the values of PVP and TLP were still on the high level at 15 min and 30 min.The values of liver perfusion (mL·min^-1·mL^-1) by different medication were as fellows: HAP: 0.22±0.06,0.24±0.06,0.31±0.07,0.26±0.05;PVP: 1.28±0.38,2.33±0.41,2.37±0.55,2.83±0.94;TLP: 1.50±0.40,2.57±0.42,2.67± 0.58,3.09±0.94,respectively.No significant difference in HAP among groups (F=2.248,P>0.05) was found,but in PVP and TLP group,significant differences (F=6.892,P<0.01;F=7.802,P<0.01) among groups were observed.In addition,superior mesenteric artery group showed higher value of PVP and TLP than other methods.CONCLUSION: Lipo-PGE₁ obviously increases liver blood perfusion,especially for portal vein perfusion.Interventional technology provides an effective pathway to improve hepatic perfusion.     

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 rosiglitazone on expressions of peroxisome proliferator-activated receptor gamma and TGF-β1 in rats with adriamycin nephrosis

AIM: To investigate the expression of renal peroxisome proliferator-activated receptor gamma (PPARγ) in rats with adrimycine nephrosis (ADR), and the effect of rosiglitazone on the activation of NF-κB p65 in renal tissue rats with ADR. METHODS: The rats were randomly assigned to following groups: control (CTR) group, adrimycine nephrosis (ADR) group, and ADR treated with rosiglitazone (5 mg·kg^-1·d^-1) group（RGL）. The levels of urinary protein, albumin, total cholesterol, triglyceride and renal function change in rats were measured after 12 weeks. The nuclear-translocation of cortical NF-κB p65 was detected by immunohistochemistry. The activity of cortical NF-κB p65 was measured by sandwich ELISA. The mRNA levels of cortical PPARγ and TGF-β₁ were detected by RT-PCR. The protein expressions of PPARγ and TGF-β₁ in the rat kidney tissues were detected by Western blotting. RESULTS: As compared to ADR group, the urinary protein excretion in RGL treatment group was decreased and the serum albumin levels were increased, but the serum total cholesterol and triglyceride were decreased and the renal pathological lesion was ameliorated. The activity of NF-κB p65 and the expressions of TGF-β₁ mRNA and protein were significantly decreased in rosiglitazone group, while the expression of PPARγ mRNA and protein was increased in RGL group (P<0.01). The correlation analysis was manifested: in ADR and RGL group, a negative correlation between the activity of NF-κB p65 and the expression of PPARγ in renal tissue (r=-0.8305, P<0.01) was observed. There was a negative correlation between the expression of TGF-β₁ and PPARγ in renal tissues (r=－0.7938, P<0.01). CONCLUSION: The expression of renal cortical PPARγ is up-regulated in rats with adrimycine nephrosis by rosiglitazone. Rosiglitazone inhibits the activation of renal cortical NF-κB p65 in part, so it inhibits the gene expression of renal TGF-β₁ and relieves the renal pathological lesion.