Ruthenium red delays the onset of cell death during oxidative stress of rat hepatocytes.

Our objective was to determine if ruthenium red protects against lethal oxidative injury of rat hepatocytes. tert-Butyl hydroperoxide, 100 mumol/L, was used to produce oxidative stress. After 2 hours of oxidative stress, cell viability was greater with than without 25 mumol/L ruthenium red (37% vs. 4.6%; P less than 0.01). Despite this cytoprotection, ruthenium red did not alter the rate or extent of glutathione depletion, malondialdehyde generation, or adenosine triphosphate depletion. In contrast, ruthenium red did retard loss of the mitochondrial membrane potential (78% vs. 42% within 30 minutes; P less than 0.01). However, the protective effect of ruthenium red could not solely be explained by preserving the mitochondrial membrane potential. Indeed, ruthenium red still improved cell survival after 2 hours of exposure to 10 mumol/L carbonyl cyanide m-chlorophenylhydrazone (CCCP), a mitochondrial uncoupler (39% vs. 13%; P less than 0.01). Cytosolic free calcium values did not change during the uncoupling of mitochondria, suggesting that the cytoprotective properties of ruthenium red cannot be explained by blocking mitochondrial calcium transport. Ruthenium red did inhibit proteolysis after 2 hours of exposure to tert-butyl hydroperoxide (434 +/- 62 vs. 242 +/- 20 nmol/10(6) cells; P = 0.016) or CCCP (236 +/- 50 vs. 99 +/- 38 nmol/10(6) cells; P = 0.04). The results indicate that ruthenium red appears to protect against hepatocellular injury by inhibiting degradative proteolytic activity. It is concluded that proteolysis may be an important mechanism contributing to lethal oxidative injury of hepatocytes.     

PEP-1-CAT融合蛋白预处理对过氧化氢诱导的内皮细胞氧化应激损伤的保护作用

目的采用体外培养的人脐静脉内皮细胞株(CRL-1730),研究 PEP-1肽介导人过氧化氢酶(CAT)穿透细胞的能力,并探讨 PEP-1-CAT 对过氧化氢(H_2O_2)诱导的内皮细胞氧化应激损伤是否有保护作用。方法构建原核表达质粒 pET15b-PEP-1-CAT,将其在基因工程菌中表达出 N 端带有6个组氨酸“标签”(His-tag)的重组蛋白,并通过金属镍螯合亲和层析对其进行纯化,将纯化得到的PEP-1-CAT 融合蛋白加入体外培养的人脐静脉内皮细胞,通过 Western blot 来分析其转导能力,同时对转导人细胞内的蛋白进行酶活性检测。然后以0.5 mmol/L H_2O_2处理细胞建立内皮细胞氧化应激损伤的模型,检测不同浓度的 PEP-1-CAT 蛋白对氧化应激下细胞存活率、乳酸脱氢酶(LDH)活性及丙二醛(MDA)含量的影响。结果 PEP-1-CAT 融合蛋白能以时间、剂量依赖的方式高效转导进入细胞内。正常内皮细胞 LDH 活性和细胞存活率分别为(540.6±65.7)U/L和100%;H_2O_2处理组 LDH活性显著高[(849.3±95.1)U/L,P<0.01],细胞存活率明显低[(37.23±5.68)%,P<0.01],MDA含量亦较正常组显著高[(8.23±1.58)nmol/L 比(2.46±1.42)nmol/L,P<0.01]。用不同浓度的PEP-1-CAT 对细胞进行预保护,均可显著提高细胞存活率、降低 LDH 释放量,并提高细胞的抗氧化能力,表现为 MDA 含量较 H_2O_2处理组低(P<0.05或<0.01)。结论 PEP-1-CAT 融合蛋白能以天然活性形式高效转导入人脐静脉内皮细胞,且转导的蛋白能有效对抗氧化应激损伤。这种蛋白转导方式,为用 CAT 防治各种与氧化应激损伤有关的疾病提供了一个新的治疗途径。     

Leptin administration exacerbates thioacetamide-induced liver fibrosis in mice

AIM: To investigate the effects of leptin administration on liver fibrosis induced by thioacetamide (TAA). METHODS: Twenty-four male C57Bl/6 mice were randomly allocated into four groups, which were intra-peritoneally given saline (2 mL/kg), leptin (1 mg/kg), TAA (200 mg/kg), TAA (200 mg/kg) plus leptin (1 mg/kg) respectively, thrice a week. All mice were killed after 4 wk. The changes in biochemical markers, such as the levels of alanine aminot-ransferase (ALT) and aspartate aminotransferase (AST) in serum and superoxide dismutase (SOD), malondialdehyde (MDA) in liver were determined. For histological analysis, liver tissues were fixed with 10% buffered formalin, embedded with paraffin. Hematoxylin-eosin (HE) staining and picric acid-Sirius red dyeing were performed. The level of α1(I) procollagen mRNA in liver tissues was analyzed by RT-PCR. RESULTS: Apparent liver fibrosis was found in TAA group and TAA plus leptin group. Compared to saline group, the levels of ALT and AST in serum and MDA in liver increased in TAA group (205.67±27.69 U/L vs50.67±10.46 U/L, 177.50±23.65 U/L vs 76.33±12.27 U/L, 2.60±0.18 nmol/mg pro vs 1.91±0.14 nmol/mg pro, P<0.01) and in TAA plus leptin group (256.17±22.50 U/L vs 50.67±10.46 U/L, 234.17±27.37 U/L vs 76.33±12.27 U/L, 2.97±0.19 nmol/mg pro vs 1.91±0.14 nmol/mg pro,P<0.01). The level of SOD in livers decreased (51.80±8.36 U/mg pro vs 81.52±11.40 U/mg pro, 35.78±6.11 U/mg pro vs 81.52± 11.40 U/mg pro, P<0.01) and the level of α1(I) procollagen mRNA in liver tissues also increased (0.28±0.04 vs 0.11± 0.02, 0.54±0.07 vs 0.11±0.02, P<0.01). But no significant changes were found in leptin group and saline group. Compared to TAA group, ALT, AST, MDA, and α1(I) procollagen mRNA and grade of liver fibrosis in TAA plus leptin group increased (256.17±22.50 U/L vs 205.67± 27.69 U/L, P<0.05; 234.17±27.37 U/L vs 177.50±23.65 U/L, P<0.05; 2.97±0.19 nmol/mg pro vs 2.60±0.18 nmol/mg pro,P<0.05; 0.54±0.07 vs 0.28±0.04, P<0.01; 3.17 vs 2.00, P<0.05), and the level of SOD in liver decreased (35.78±6.11 U/mg pro vs 51.80±8.36 U/mg pro, P<0.05). There were similar changes in the degree of type I collagen deposition confirmed by picric acid-Sirius red dyeing. CONCLUSION: Leptin can exacerbate the degree of TAA-induced liver fibrosis in mice. Leptin may be an important factor in the development of liver fibrosis.     

Prognostic indicators in the initial presentation of Pneumocystis carinii pneumonia

We prospectively evaluated 150 consecutive patients with Pneumocystis carinii pneumonia (PCP) as their sole initial manifestation of AIDS (group 1). Admission laboratory and radiographic criteria were analyzed for diagnostic and prognostic indicators and compared with those of patients presenting with non-PCP pulmonary manifestations of AIDS (group 2). Mean admission serum LDH level was 465 +/- 67 IU/L in PCP patients (group 1) and 211 +/- 28 IU/L in group 2 (p less than 0.01). Seventy-eight percent of PCP patients (117 of 150) survived. Comparing survivors with nonsurvivors, the mean admission LDH level was 394 +/- 45 vs 717 +/- 51 IU/L (p less than 0.01), and the mean P(A-a)O2 gradient was 42 +/- 6 vs 55 +/- 6 mm Hg (p less than 0.05). Serum LDH levels and P(A-a)O2 gradients have diagnostic and prognostic implications in patients with AIDS-related PCP.     

Intracellular glutathione and bronchoalveolar cells in fibrosing alveolitis: effects of N-acetylcysteine.

Extracellular glutathione deficiency and exaggerated oxidative stress may contribute to the pathogenesis of fibrosing alveolitis (FA). High-dose N-acetylcysteine (NAC) supplementation partially reverses extracellular glutathione depletion and oxidative damage, but effects on intracellular glutathione are unknown. Intracellular total glutathione (GSHt) and activation of bronchoalveolar lavage cells (BAC) obtained from 18 FA patients (9 males, aged 52+/-2 yrs), before and after 12 weeks of oral NAC (600 mg t.i.d.), were assessed. Eight healthy nonsmokers (2 males, aged 36+/-6 yrs) served as a control group. Intracellular GSHt was decreased in FA (1.57+/-0.20 nmol 1x10(6) BAC(-1) versus 2.78+/-0.43 nmol x 10(6) BAC(-1)). After NAC treatment, the intracellular GSHt content increased (1.57+/-0.20 versus 1.87+/-0.19 nmol x 1 x 10(6) BAC(-1)). The spontaneous oxidative activity of BAC decreased after NAC treatment (2.7+/-0.8 versus 1.0+/-0.2 nmol x 1 x 10(6) BAC(-1) x h(-1)). Interleukin-8 concentration (82.1+/-31.5 versus 80.0+/-22.6 pg x mL bronchoalveolar fluid (BALF), nonsignificant (NS)) and myeloperoxidase activity (1.93+/-0.64 versus 1.55+/-0.47 mU x mL(-1) BALF, NS) did not change significantly, but were found to be inversely correlated to intracellular GSHt. In conclusion, high-dose N-acetylcysteine supplementation increases intracellular glutathione levels slightly. This increase is associated with a mild reduction of oxidative activity but not with a reduction of bronchoalveolar cell activation in these patients.     

吸氧对慢性缺氧高二氧化碳大鼠肺血管L-精氨酸转运的影响

目的　探讨慢性缺氧 (O2 )高二氧化碳 (CO2 )对大鼠肺动脉L 精氨酸 (L Arg)转运的影响与吸氧的作用。方法　将 4 0只大鼠以随机区组设计法分成 4组 ,用 0 2mmol/L和 5 0mmol/L [3 H] Arg将肺动脉孵育 ,测定其对 [3 H] L Arg的摄取率、一氧化氮合酶 (NOS)活性与一氧化氮 (NO2 /NO3)含量。每组 1 0只。正常对照组 (A组 )、慢性缺O2 4周后伴高CO2 4周组 (B组 )、慢性缺O2 4周伴高CO24周后吸空气 4周组 (C组 )及慢性缺O2 4周伴高CO2 4周后吸O2 4周组 (D组 )。结果　 (1 )肺动脉平均压 (mPAP)、右心室 (RV)和左心室 +室间隔 (LV +S)重量比值 (RV/LV +S) :B组 (33% )与A组(35 % )比较差异有显著性 (P均 <0 0 1 ) ;D组 (2 4 % )与C组 (2 4 % )比较 ,差异也有显著性 (P均 <0 0 5 )。 (2 )离体孵育的肺动脉摄取低浓度 (0 2mmol/L)和高浓度 (5 0mmol/L) [3 H] L Arg比较 :B组分别为 [(3 0 4± 0 1 6 ) μmol·g-1 min-1 ]、[(8 1 2± 0 1 4 ) μmol·g-1 ·min-1 ],A组分别为 [(4 6 2± 0 5 5 )μmol·g-1 ·min-1 ]、[(1 1 2 4± 1 0 2 ) μmol·g-1 ·min-1 ],A、B两组比较差异有显著性 (P均 <0 0 1 ) ;而D组分别为 [(4 30± 0 1 8) μmol·g-1 ·min-1 ]、[(1 2 31± 0 6 5 ) μmol·g-1 ·m     

西罗莫司联用阿托伐他汀对大鼠血管平滑肌细胞氧化应激损伤和一氧化氮合酶的影响

目的探讨西罗莫司和阿托伐他汀联合使用对大鼠血管平滑肌细胞氧化应激损伤和一氧化氮合酶(NOS)的影响。方法取大鼠血管平滑肌细胞进行实验,分为空白组、DMSO组、西罗莫司组(100nmol/L)、阿托伐他汀组(3μmol/L)和联合组(西罗莫司100nmol/L加阿托伐他汀3μmol/L)。实验各组细胞给予相应药物干预2h后,加入三丁基过氧化氢诱导氧化应激损伤,24h后检测各项指标。结果与空白组比较,DMSO组、西罗莫司组、阿托伐他汀组和联合组细胞增殖率明显下降(P<0.01)。与空白组和DMSO组比较,阿托伐他汀组和联合组超氧化物歧化酶水平明显上升和丙二醛水平明显下降(P<0.05,P<0.01)。与空白组、DMSO组、西罗莫司组比较,阿托伐他汀组和联合组诱导型一氧化氮合酶(iNOS)mRNA和蛋白表达明显下降(P<0.01);联合组iNOS mRNA和蛋白表达较阿托伐他汀组明显下降(P<0.05,P<0.01)。结论在氧化应激状态下,西罗莫司和阿托伐他汀均能抑制大鼠血管平滑肌细胞增殖和抗氧化损伤,维持NOS系统平衡,联合应用的效果优于单独应用。     

Study on hepatoprotective effect of peptide S-8300 from shark liver

AIM: To explore the effects of peptide S-8300 from shark liver (S-8300) on liver function as well as in regulating immune functions in experimental injury models. METHODS: Mice were administered with different doses of S-8300 for four consecutive days, followed by mice injected with tetrachloromethane (CCI4) on d 3. The activity of ALT, AST, LDH, SOD and contents of MDA and GSH in the mice liver were tested. And mice were treated with Cy (100 mg/kg) at the beginning of the experiment to induce immunosuppression model. The S-8300 groups were treated with S-8300 seven days after the beginning of Cy administration. The effects of S-8300 on the formulation of serum hemolysin and the content of IL-2 in serum in the immunosuppression mice were observed. RESULTS: S-8300 obviously decreased the level of ALT (52.2±11.0 U/dL vs135.9±6.5 U/dL, P<0.01), AST (67.5±6.9 U/dL vs 238.8±8.7 U/dL, P<0.01), LDH (155.1±46.8 U/dL vs 240.4±6.0 U/dL, P<0.01) & MDA (0.64?.027 nmol/mg vs 1.06±0.040 nmol/mg, P<0.01) and increased SOD (24.51±1.01 U/mg vs 19.05±0.73 U/mg, P<0.01) & GSH (24.17±0.91 μg/mg vs 14.93±0.45 μg/mg, P<0,01) in mice liver damaged by CCI4. S-8300 also markedly improved the formulation of serum hemolysin (0.094±0.005 A540 vs 0.063±0.006 A540, P<0.01) and increased the level of IL-2 (9.74±1.16 pg/mL vs 5.81±0.87 pg/mL, P<0.01) in serum of the immunosuppression mice. CONCLUSION: The results suggested S-8300 has significant hepatoprotective, immunomodulatory and inhibiting of lipid peroxidation activity.     

丝裂素活化蛋白激酶参与心肌缺氧预处理的延迟保护作用

目的　探讨丝裂素活化蛋白激酶 (mitogen- activated protein kinase,MAPK)在心肌缺氧预处理延迟保护中的作用。方法　在培养乳鼠心肌细胞缺氧预处理的模型上 ,检测预处理后即刻、1h、6 h和 12 h的 MAPK活性变化 ,观察细胞缺氧 /复氧损伤后、延迟预处理后及蛋白激酶 C(PKC)抑制剂 chelerythrine(Ch)干预后的细胞存活率、L DH的释放、MDA含量和 SOD活性。结果　 MAPK活性在预处理后即刻明显增加 (P<0 .0 1) ,在 6 h后降至或接近对照水平。与未预处理组心肌细胞缺氧 /复氧损伤相比较 ,预处理后 2 4 h心肌细胞存活率增高 [(5 8.6 4± 5 .5 3) %vs (44 .2 9± 4 .2 7) % ,P<0 .0 1],L DH[(5 9.5 0± 11.0 8) U/ L vs(83.17± 13.6 9) U/ L,P<0 .0 1]和 MDA含量[(2 .33± 0 .4 9) nmol/ L vs(3.2 9± 0 .2 6 ) nmol/ L,P<0 .0 1]均降低 ,SOD活性增加 [(2 1.5 3± 3.6 3) n U/ m l vs(12 .86± 2 .6 8) n U/ ml,P<0 .0 1]。PKC抑制剂 chelerythrine可消除预处理的延迟保护作用。结论　预处理 2 4 h心肌细胞对再次缺氧 /复氧有保护作用 ,PKC、MAPK均参与心肌细胞预处理后的延迟保护作用     

老年脑梗死患者血清对氧磷酶1活性与氧化应激的关系及其在动脉粥样硬化中的作用

目的 探讨老年脑梗死患者血清对氧磷酶1活性与氧化应激的关系及其在动脉粥样硬化中的作用.方法 通过DSA检查确诊颈动脉狭窄的老年脑梗死患者72例作为研究对象(其中轻度狭窄33例,中度狭窄24例,重度狭窄15例),以非脑血管病健康体检者38例作为对照组,用分光光度计法、黄嘌呤氧化酶法和硫代巴比妥酸反应物质法分别测定血清对氧磷酶1活性、超氧化物歧化酶和丙二醛含量,分析对氧磷酶1活性与超氧化物歧化酶、丙二醛之间的关系.结果 脑梗死组患者血清对氧磷酶1活性(95.62±18.26 ku/L)和超氧化物歧化酶含量(69.59±10.56 ku/L)显著低于对照组(分别为168.36±27.82 ku/L和98.34±13.42 ku/L,P<0.01],而丙二醛含量(24.46±5.68nmol/L)显著高于对照组(15.64±8.26 nmol/L,P<0.01).轻度、中度和重度狭窄组患者对氧磷酶1活性(分别为112.48±19.32、98.64±10.84和81.95±13.42 ku/L)、超氧化物歧化酶(分别为80.62±13.26、70.26±14.09和58.82±10.06ku/L)和丙二醛含量(分别为19.52±8.48、23.56±9.81和27.28±9.89nmol/L)差异均有显著性(均P<0.01),并且对氧磷酶1活性和超氧化物歧化酶含量随颈动脉狭窄程度加重,呈逐渐下降的趋势,而丙二醛含量随颈动脉狭窄程度加重呈上升趋势.相关分析表明,对氧磷酶1活性与超氧化物歧化酶含量正相关(r=0.628,P<0.01),而与丙二醛含量负相关(r=－0.541,P<0.01).结论 老年脑梗死患者血清对氧磷酶1活性降低及氧化应激增强,对氧磷酶1活性和氧化应激及其复杂的相互作用参与动脉粥样硬化发生和发展.     

Erythrocyte susceptibility to oxidative stress and antioxidant status in patients with type 1 diabetes

In this study, malondialdehyde (MDA) level as an index of erythrocyte susceptibility to oxidative stress and antioxidant defense system (glutathione level (GSH), glutathione peroxidase enzyme activity (GPx) in erythrocytes and ferric reducing ability of plasma (FRAP) as the total plasma antioxidant capacity were measured in 35 patients with type 1 diabetes and 28 age and sex-matched normal subjects. MDA level was significantly elevated in diabetic patients (650.9+/-144.3 nmol/g versus 476.5+/-138.5 nmol/g Hb, P<0.001). The level of MDA was positively correlated with duration of diabetes (r= 0.29, P<0.05) and HbA(1C) (r= 0.39, P<0.05) and negatively with FRAP (r= -0.3, P<0.05). The level of GSH and FRAP were lower in patients than controls (7.05+/-1.6 micromol/g versus 8.24+/-0.9 micromol/g Hb, and 389.05+/-82.3 micromol/l versus 520.4+/-124.1 micromol/l, respectively, P<0.001). GPx activity was not significantly different between the two groups. GSH and FRAP were negatively correlated with HbA(1C) (r= -0.334, P<0.01 and r= -0.5, P<0.01, respectively). In conclusion, there seems to be an increased susceptibility to oxidative stress and decreased antioxidant defense in patients with type 1 diabetes, which may be due to poor glycemic control.     

Effects of selenium on peripheral blood mononuclear cell membrane fluidity, interleukin-2 production and interleukin-2 receptor expression in patients with chronic hepatitis

AIM: To study the effect of selenium on peripheral blood mononuclear cell (PBMC) membrane fluidity and immune function in patients with chronic hepatitis. METHODS: PBMCs were pretreated with selenium (1.156x10(-7) mol/L) for 6 h in vitro or extracted directly from patients after administration of selenium-yeast continuously for 8-12 wk (200 microg/d), and then exposed to Con-A for 48 h. The membrane fluidity, interleukin-2 (IL-2) production and interleukin-2 receptor (IL-2R) expression in PBMCs and malondialdehyde (MDA) concentration in medium and lipid peroxide (LPO) in plasma were determined. RESULTS: The PBMC membrane fluidity, IL-2 production and IL-2R expression in patients with chronic hepatitis were significantly lower than those in healthy blood donators (particle adhesive degree R, 0.17+/-0.01 vs 0.14+/-0.01, P<0.01; IL-2, 40.26+/-9.55 vs 72.96+/-11.36, P<0.01; IL-2R, 31.05+/-5.09 vs 60.58+/-10.56, P<0.01), and the MDA concentration in medium in patients with chronic hepatitis was significantly higher than that in healthy blood donators (1.44+/-0.08 vs 0.93+/-0.08, P<0.01). Both in vitro and in vivo administration of selenium could reverse the above parameters. CONCLUSION: Supplement of selenium can suppress lipid peroxidation, and improve PBMC membrane fluidity and immune function in patients with chronic hepatitis.     

高原肺水肿患者血浆纤溶系统变化及卡托普利的影响

目的　观察高原肺水肿 (HAPE)患者血浆纤溶系统的变化及卡托普利对其的影响 ,探讨其发病机制。方法　 72例高原肺水肿患者分为卡托普利组 (35例 )和常规组 (37例 ) ,并以 2 0名健康志愿者作为对照。所有患者治疗前、后均测定血浆组织型纤溶酶原激活物 (tPA)及纤溶酶原激活物抑制物 (PAI 1)的活性。结果　血浆tPA含量卡托普利组 (A组 )治疗前、后分别为 (0 4 0± 0 14 )× 10 3 IU/L、(0 5 8± 0 13)× 10 3 IU/L ,常规组 (B组 )治疗前、后分别为 (0 39± 0 19)× 10 3 IU/L、(0 4 9± 0 16 )×10 3 IU/L ,正常对照组 (C组 )为 (0 5 9± 0 17)× 10 3 IU/L ;A、B两组治疗前、后比较差异均有显著性(P <0 0 1、<0 0 5 ) ;血浆PAI 1含量A组治疗前、后分别为 (6 6± 1 8)× 10 3 AU/L、(4 9± 1 5 )×10 3 AU/L ,B组治疗前、后分别为 (6 6± 1 6 )× 10 3 AU/L、(5 8± 1 7)× 10 3 AU/L ,C组为 (4 9± 1 3)×10 3 AU/L。A、B两组治疗前、后比较差异均有显著性 (P <0 0 1、 <0 0 5 )。结论　HAPE患者纤溶系统呈失衡性改变 ,卡托普利有恢复其平衡的治疗作用。     

Inhibition of protein kinase C by staurosporine increases estrogen secretion by rat Sertoli cells

We have examined the effect of inhibition of protein kinase C activity by staurosporine on estradiol secretion by Sertoli cells isolated from 8-10 days old rats. Staurosporine lead to a dose-related increase in estradiol secretion independent of FSH, such that with 100 nmol/l staurosporine basal estradiol levels increased 10-fold. The maximal response seen with staurosporine alone (100 nmol/l) or in combination with FSH (0.4-8 IU/l) was similar to that seen with a saturating dose of FSH (8 IU/l). There was no evidence of synergy between FSH and staurosporine. Activation of protein kinase C by phorbol 12,13 dibutyrate (10(-7) mol/l) resulted in a 53-74% inhibition of estradiol production provoked by FSH (8 IU/l), staurosporine (5-100 nmol/l) or staurosporine in combination with FSH. Staurosporine (5-100 nmol/l), in the absence or presence of FSH, was unable to overcome inhibition of estradiol secretion by phorbol ester, indicating the presence of at least two independent binding sites on protein kinase C for these molecules. Forskolin (1 mumol/l)- and dibutyryl cAMP (1 mmol/l)-stimulated estradiol secretion was inhibited by 31 +/- 5% and 64 +/- 5% respectively, by phorbol 12,13 dibutyrate (10(-7) mol/l). We conclude that FSH-induced estradiol secretion in immature rat Sertoli cells is affected by protein kinase C activity.     

DNA damage, apoptosis and cell cycle changes induced by fluoride in rat oral mucosal cells and hepatocytes

AIM:To study the effect of fluoride on oxidative stress,DNA damage and apoptosis as well as cell cycle of ratoral mucosal cells and hepatocytes.METHODS:Ten male SD rats weighing 80～120 g wererandomly divided into control group and fluoride group,5 animals each group.The animals in fluoride group hadfree access to deionized water containing 150 mg/L so-dium fluoride(NaF).The animals in control group weregiven distilled water.Four weeks later,the animals werekilled.Reactive oxygen species(ROS)in oral mucosa andliver were measured by Fenton reaction,lipid peroxida-tion product,malondialdehyde(MDA),was detected bythiobarbituric acid(TBA)reaction,reduced glutathione(GSH)was assayed by dithionitrobenzoic acid(DTNB)reaction.DNA damage in oral mucosal cells and hepa-tocytes was determined by single cell gel(SCG)electro-phoresis or comet assay.Apoptosis and cell cycle in oralmucosal cells and hepatocytes were detected by flowcytometry.RESULTS:The contents of ROS and MDA in oral mucosaand liver tissue of fluoride group were significantly high-er than those of control group(P<0.01),but the level ofGSH was markedly decreased(P<0.01).The contents ofROS,MDA and GSH were(134.73±12.63) U/mg protein,(1.48±0.13)mmol/mg protein and(76.38±6.71)mmol/mg protein in oral mucosa respectively,and(143.45±11.76)U/mg protein,(1.444-0.12)mmol/mg protein and(78.83±7.72)mmol/mg protein in liver tissue respective-ly.The DNA damage rate in fluoride group was 50.20%in oral mucosal cells and 44.80% in hepatocytes,higherthan those in the control group(P<0.01).The apop-tosis rate in oral mucosal cells was(13.63±1.81)% influoride group,and(12.76±1.67)% in hepatocytes,higher than those in control group.Excess fluoride coulddifferently lower the number of oral mucosal cells andhepatocytes at G_0/G_1 and S G_2/M phases(P<0.05).CONCLUSION:Excess fluoride can induce oxidative stress and DNA damage and lead to apoptosis and cellcycle change in rat oral mucosal cells and hepatocytes.     

Gonadotropin treatment increases homocysteine levels in idiopathic hypogonadotropic hypogonadism: an indirect effect mediated by changes in body composition

The main objective of the present study was to examine the alterations in plasma total homocysteine (tHcy) concentrations during a testosterone-deficient state and after gonadotropin treatment for 6 Months in patients with idiopathic hypogonadotropic hypogonadism (IHH). Thirty-five newly diagnosed male patients with IHH (mean age 21.34+/-1.53 years) and 29 age- and body mass index-matched healthy males (mean age 21.52+/-1.77 years) were recruited into the study. Pretreatment levels of free testosterone (1.51+/-0.66 pg/ml), estradiol (21.37+/- 4.37 pg/ml), FSH (0.91+/-0.24 IU/l) and LH (1.25+/- 0.53 IU/l) were lower than controls (25.17+/-3.06 pg/ml, 31.00+/-4.96 pg/ml, 3.14+/-1.62 IU/l and 4.83+/-1.65 IU/l respectively) (P<0.001). They increased significantly after treatment (18.18+/-1.59 pg/ml, 27.97+/- 4.25 pg/ml, 2.41+/-0.27 IU/l and 2.79+/-0.19 IU/l respectively) (P<0.001). Patients with IHH had lower tHcy levels than controls (10.14+/-1.34 and 12.58+/- 2.29 micro mol/l respectively) (P<0.001). Plasma tHcy concentrations increased significantly (12.63+/-1.44 micromol/l) after 6 months of treatment (P<0.001). As compared with the controls, pretreatment levels of serum creatinine (63.54+/-13.01 vs 82.84+/-16.69 micromol/l), hemoglobin (12.98+/-0.56 vs 13.83+/-0.71 g/dl) and hematocrit (39.29+/-2.01 vs 41.38+/-1.95%) were significantly lower (P<0.001), and they increased significantly following treatment (80.24+/-11.93 micromol/l, 13.75+/-0.49 g/dl and 41.26+/-1.78% respectively) (P<0.001). The pretreatment folic acid and vitamin B(12) levels were significantly higher in patients when compared with controls (14.87+/-5.68 vs 12.52+/-4.98 nmol/l, P=0.034 and 289.75+/-92.34 vs 237.59+/-108.17 pmol/l, P=0.002 respectively). They decreased significantly after treatment (11.29+/-3.31 nmol/l and 228.51+/-54.33 pmol/l respectively) (P<0.001). The univariate and multivariate regression analysis results showed that only changes in creatinine, creatinine clearance, vitamin B12 and folic acid were independently associated with changes in tHcy levels in patients with IHH. In conclusion, the increase in plasma tHcy concentrations following gonadotropin treatment seems to be largely independent of changes in androgen levels.     

Alterations in the oxidant-antioxidant status in prepubertal children with growth hormone deficiency: effect of growth hormone replacement therapy

OBJECTIVE: Growth hormone deficiency (GHD) in adults is associated with increased oxidative stress determined by the underlying GH-IGF-1 axis alterations. Despite GHD being a common diagnosis in children with short stature, no data on the oxidant/antioxidant status are available in this age group. This study was designed to detect differences in oxidative stress parameters between prepubertal GH-deficient children and healthy controls. Furthermore, the effect of 12 months of conventional GH replacement (rGH) on oxidant-antioxidant status was evaluated in the GHD group only. PATIENTS: Ten (nine males and one female) prepubertal children (mean age 9.1 +/- 1.3 years) with GHD were recruited and matched for sex and age (9.2 +/- 1.9 years) with 20 healthy controls (18 males and two females). MEASUREMENTS: At study entry, lag phase, an index of susceptibility of low density lipoprotein (LDL) to in vitro oxidation, malondialdehyde (MDA) and vitamin E were measured in all subjects. These parameters were also evaluated in GH-deficient children after 12 months of rGH treatment. RESULTS: The lag phase was significantly decreased in GH-deficient children compared to healthy controls (15.50 +/- 7.4 vs. 43.00 +/- 9.2 min; P = 0.0007), while MDA was significantly increased (1.33 +/- 0.38 vs. 0.46 +/- 0.10 nmol/mg; P = 0.0006). Vitamin E levels were significantly decreased (22.44 +/- 9.57 vs. 35.38 +/- 16.49 micromol/l; P = 0.001). IGF-1 and IGFBP-3 correlated directly to lag phase (r = 0.48; P = 0.01; r = 0.63, P = 0.002, respectively) and to vitamin E (r = 0.59, P = 0.003; r = 0.58, P = 0.006, respectively). By contrast, IGF-1 and IGFBP-3 correlated indirectly to MDA (r = -0.47, P = 0.01; r =-0.65, P = 0.002, respectively). After 1 year of rGH therapy, lag phase (39.32 +/- 15.24 min; P = 0.005) and vitamin E (34.9 +/- 7.7 micromol/l; P = 0.005) increased significantly, while MDA decreased significantly (0.71 +/- 0.42 nmol/mg; P = 0.005), reaching normal levels. CONCLUSIONS: These data show that children with GHD have substantially increased oxidative stress parameters compared to healthy controls and demonstrate a normalization of these parameters after 1 year of rGH therapy.