Effect of Heavy Metals on Dopamine,Noradrenaline and Serotonin Uptake and Release in Rat Brain Synaptosomes

Abstract: The effects of some heavy metals on the initial high affinity uptake and spontaneous release of tritiated dopamine (³H-DA), noradrenaline (³H-NA) and 5-hydroxytryptamine (³H-5-HT) were studied in vitro in rat striatal, cortical and hypothalamic synaptosomes, respectively. As uptake inhibitors, metals were quite inactive in these conditions. At 10 μM Cu²⁺ was most potent, inhibiting ³H-DA and ³H-5-HT uptake nearly completely while inhibition of ³H-NA uptake varied. ³H-DA uptake was in addition inhibited slightly by Zn²⁺, sometimes by Sn²⁺ but never by Co²⁺, Hg²⁺ or Mn²⁺. Unexpectedly Pb²⁺ and Cd²⁺ tended to increase the synaptosomal ³H-DA uptake. ³H-5-HT uptake was affected least while that of ³H-NA showed some diversity. Zn²⁺, Pb²⁺ and Sn²⁺ induced inhibition of ³H-NA uptake possibly by direct interference with ³H-NA. As to the spontaneous release of tritiated amines during short incubation from preloaded synaptosomes, Cd²⁺ decreased that of ³H-DA at high concentrations but Hg²⁺, Pb²⁺, Sn²⁺ and Zn²⁺ were ineffective. The results suggest that in vitro the uptake and the release of ³H-DA are more affected than those of other amines. The inhibitory mechanisms of monoamine uptake may include both direct effects on synaptosomes and indirect ones by interference with the amines themselves.     

银杏叶提取物对糖尿病大鼠行为学及大脑皮质和海马钠-钾ATP酶活性的影响

目的:研究大鼠长期糖尿病后行为学与大脑皮质和海马Na -K ATP酶活性的变化以及银杏叶提取物(Egb)的影响.方法:大鼠腹腔注射佐链霉素55 mg·kg-1建立糖尿病模型,以旷场分析法和Morris水迷宫法考察学习记忆能力,检测大脑皮质和海马的Na -K ATP酶活性.结果:Egb可明显升高Na -K ATP酶活性,缩短中央格停留时间、水迷宫实验逃避潜伏期时间,提高探洞次数和搜寻平台策略成绩.结论:Egb可提高糖尿病大鼠大脑皮质和海马的Na -K ATP酶活性,改善学习记忆能力.     

Tetrahydro-β-carbolines and Corresponding Tryptamines: In Vitro Inhibition of Serotonin,Dopamine and Noradrenaline Uptake in Rat Brain Synaptosomes

Abstract The structure activity relationships of tryptolines and some other β-carbolines and tryptamines as inhibitors of serotonin (5-HT), dopamine (DA) and noradrenaline (NA) uptake were studied in rat brain synaptosomes. All β-carbolines inhibited to higher degree the uptake of 5-HT than that of DA or NA (IC50's 5–100 times lower). The most potent tryptoline derivative was 6-hydroxy-tetrahydro-β-carboline (5-hydroxytryptoline, 6-OH-THBC) with an IC50 of 5.0× 10^-7M at a 5-HT concentration of 10^-7M. 6-Methoxy-tetrahydro-β-carboline (5-methoxytryptoline) was slightly weaker; the inhibition of 5-HT uptake and DA uptake being competitive. Also tetrahydro-β-carboline (tryptoline) was more potent than its 1-methylderivative, tetrahydroharmane (methtryptoline) or norharmane (β-carboline). All of them were, however, weaker inhibitors of 5-HT uptake than the freely rotating indoleamines N-methyl-tryptamine (N-Me-T) or 5-HT itself. N-Me-T and 5-HT were also more potent inhibitors of DA and NA uptake than most of the β-carbolines, DA uptake, however, was inhibited better by 6-OH-THBC than by 5-HT or N-Me-T. Tetrahydro-β-carbolines may inhibit 5-HT uptake also in vivo but it is unlikely that catecholamine uptake is affected.     

Effect of interaction of heavy metals on (Na+ -K+) ATPase and the uptake of 3H-DA and 3H-NA in rat brain synaptosomes

The effect of interaction of Mn2+, Pb2+ and Cd2+ on (Na+ -K+) ATPase and uptake of labelled dopamine (3H-DA) and labelled noradrenaline (3H-NA) were studied in vitro in rat brain synaptosomes. The inhibition of (Na+ -K+) ATPase by Pb2+ and Cd2+ alone was concentration dependent, however, Mn2+ had almost no effect on the activity of this enzyme. Interaction of Cd2+ with either Pb2+ or Mn2+ was most powerful in inhibiting the activity of synaptosomal transport ATPase. Lower concentrations of Pb2+ increased while higher concentrations inhibited synaptosomal uptake of 3H-DA and 3H-NA. Lower concentrations of Cd2+ increased the uptake of 3H-DA while at concentrations of 100 microM, the uptake was inhibited, this metal had strong inhibitory effect on the uptake of 3H-NA. Mn2+ had inhibited the uptake of labelled amines. Interaction of Mn2+ with Pb2+ or Cd2+ produced inhibition on the uptake of 3H-DA and 3H-NA. The results of the uptake of biogenic amines in the presence of metal ions apparently had no correlation with the activity of (Na+ -K+) ATPase which is involved in the active transport of cations across cell membranes.     

复合离子盐对老年人细胞内Na+、K+、Ca2+的影响及其机制

目的：观察复合离子盐对老年人细胞内Na^＋、K^＋、Ca^2＋及红细胞膜钠泵和钙泵活性的影响。方法：在天津市河东区社区中抽取226例老年人作为研究对象．其中高血压者112例。正常血压者114例。两者再随机分为离子盐组和普通加碘盐组．分别给予复合离子盐和普通加碘盐摄入，6个月后观察研究对象细胞内Na^＋、K^＋、Ca^2＋及钠泵、钙泵活性的变化。结果：6个月时高血压患者中离子盐组细胞内钠、钙离子浓度低于基线水平（P〈0．05），但钾离子无明显变化。离子盐组钠泵、钙泵活性均明显高于基线水平（P〈0．05），但在正常血压者中，2组与基线水平比较差异无统计学意义。结论：复合离子盐可增强钠泵、钙泵活性，使细胞内的钠、钙含量减少。     

Interaction between theophylline and ouabain in the rabbit heart: Effect on (Na + K)-ATPase

In electrically stimulated rabbit ventricular strips, theophylline (0.3–30 M) antagonized the increased contractility produced by ouabain (0.8 μM). Initial velocity of specific [³H]ouabain binding to homogenates prepared from the muscle strips was used to determine the fraction of binding sites occupied by ouabain. Theophylline decreased the binding of ouabain to (Na⁺ + K⁺)-ATPase. It is concluded that the effect of theophylline on ouabain-induced positive inotropism may be mediated by decreased ouabain binding to (Na⁺ + K⁺)-ATPase.     

青蒿琥酯钠对体外大鼠红细胞膜钠-钾交换ATP酶的抑制

体外测定青蒿琥酯钠(SA)对大鼠红细胞膜Na~( )-K~( )-交换ATP酶活性的影响.方法:在反应系统中分别加入不同浓度的SA(0,0.5,1,5和10 μmol·L~(-1)),通过测定反应系统中释放的无机磷含量,计算酶活性.结果:随着SA浓度(O,0.5,1,5和10 μmol·L~(-1))的增高,对Na~( )-K~( )-交换ATP酶活性的抑制作用也随之增强,抑制率分别为15％,29％,46％和75％.将底物ATP浓度增加为125,250,375和500 μmol·L~(-1),进行了酶的动力学测定.用直线回归分析作Eadie-Hofstee动力学曲线,结果表明,SA对该酶的抑制作用为竞争性抑制.结论:提示SA可影响宿主红细胞膜的离子转运及膜的功能.     

鞘内注射布美他尼对大鼠急性疼痛行为及钠钾氯联合转运蛋白1表达的影响

目的探讨鞘内注射布美他尼对大鼠术后痛觉过敏形成的作用机制,为临床研究及应用提供理论参考。方法采用随机数字表法将大鼠分为对照组、注药组、手术组及实验组。采用热辐射法(热痛敏)、von Frey细丝法(机械痛敏)及疼痛累计评分法(疼痛保护反应)观察、记录术前及术后2、4、6 h大鼠的行为学改变,采用免疫组化,荧光显微镜观察各组术后2、4、6 h背根神经节(DRG)的NKCC1表达,并行阳性细胞计数。结果手术组与实验组术后各时间点的热痛阈均降低(P<0.05);实验组热痛阈明显高于手术组(P<0.05)。注药组大鼠在注药后2 h的机械痛阈升高(P<0.05),手术组大鼠的机械痛阈明显低于实验组(P<0.05)。手术组与实验组术后疼痛累计评分均升高(P<0.05),但手术组明显高于实验组(P<0.05)。手术组及实验组在各时间点阳性细胞计数均明显增多(P<0.01);组间比较,实验组的阳性细胞计数明显少于手术组(P<0.01)。结论鞘内注射布美他尼能提高切口痛模型大鼠的热痛阈值及机械痛阈值,降低疼痛累计评分,减少切口痛模型大鼠DRG的NKCC1的表达,提示布美他尼对急性疼痛过敏的形成有抑制作用,其抗伤害作用可能与抑制NKCC1活动有关。NKCC1对急性痛觉过敏形成与维持起重要作用。     

槲皮素对大鼠钠钾腺苷三磷酸酶和钙镁腺苷三磷酸酶的影响(英文)

槲皮素(Que)ig 200mg·kg~(-1),qd×14d可显著降低大鼠心肌和脑钠钾腺苷三磷酸酶(Ⅰ)的活力及心肌钙镁腺苷三磷酸酶(Ⅱ)的活力;槲皮素100mg·kg~(-1)降低心肌Ⅰ的活力,但对脑Ⅰ无明显影响。实验结果提示,大鼠心肌Ⅰ对Que的反应较脑Ⅰ敏感;槲皮素也能显著抑制心肌Ⅱ的活力。     

Effects of lead on Na+, K+‐ATPase and hemolymph ion concentrations in the freshwater mussel Elliptio complanata

Freshwater mussels are an imperiled fauna exposed to a variety of environmental toxicants such as lead (Pb) and studies are urgently needed to assess their health and condition to guide conservation efforts. A 28‐day laboratory toxicity test with Pb and adult Eastern elliptio mussels (Elliptio complanata) was conducted to determine uptake kinetics and to assess the toxicological effects of Pb exposure. Test mussels were collected from a relatively uncontaminated reference site and exposed to a water‐only control and five concentrations of Pb (as lead nitrate) ranging from 1 to 245 μg/L in a static renewal test with a water hardness of 42 mg/L. Endpoints included tissue Pb concentrations, hemolymph Pb and ion (Na⁺, K⁺, Cl^?, Ca²⁺) concentrations, and Na⁺, K⁺‐ATPase enzyme activity in gill tissue. Mussels accumulated Pb rapidly, with tissue concentrations increasing at an exposure‐dependent rate for the first 2 weeks, but with no significant increase from 2 to 4 weeks. Mussel tissue Pb concentrations ranged from 0.34 to 898 μg/g dry weight, were strongly related to Pb in test water at every time interval (7, 14, 21, and 28 days), and did not significantly increase after day 14. Hemolymph Pb concentration was variable, dependent on exposure concentration, and showed no appreciable change with time beyond day 7, except for mussels in the greatest exposure concentration (245 μg/L), which showed a significant reduction in Pb by 28 days, suggesting a threshold for Pb binding or elimination in hemolymph at concentrations near 1000 μg/g. The Na⁺, K⁺‐ATPase activity in the gill tissue of mussels was significantly reduced by Pb on day 28 and was highly correlated with tissue Pb concentration (R² = 0.92; P = 0.013). The Na⁺, K⁺‐ATPase activity was correlated with reduced hemolymph Na⁺ concentration at the greatest Pb exposure when enzyme activity was at 30% of controls. Hemolymph Ca²⁺ concentration increased significantly in mussels from the greatest Pb exposure and may be due to remobilization from the shell in an attempt to buffer the hemolymph against Pb uptake and toxicity. We conclude that Na⁺, K⁺‐ATPase activity in mussels was adversely affected by Pb exposure, however, because the effects on activity were variable at the lower test concentrations, additional research is warranted over this range of exposures. © 2010 Wiley Periodicals, Inc. Environ Toxicol, 2012.     

Diet induced obesity in rats reduces NHE3 and Na+/K+‐ATPase expression in the kidney

The consumption of a high fat diet (HFD) is associated with proteinuria and altered sodium handling and excretion, which can lead to kidney disease. In the proximal tubule, the Na⁺/H⁺ Exchanger 3 (NHE3) is responsible for normal protein reabsorption and the reabsorption of approximately 70% of the renal sodium load. It is the Na⁺/K⁺‐ATPase that provides the driving force for the reabsorption of sodium and its exit across the basolateral membrane. This study investigates the effects that consumption of a HFD for 12 weeks has on NHE3 and Na⁺/K⁺‐ATPase expression in the kidney. Western blot analysis identified a significant reduction in NHE3 and its modulator, phosphorylated protein kinase B, in renal lysate from obese rats. In the obese rats, a reduction in NHE3 expression in the proximal tubule may impact on the acidification of endosomes which are responsible for albumin uptake, suggesting a key role for the exchanger in protein endocytosis in obesity. Western blot analysis identified a reduction in Na⁺/K⁺‐ATPase which could also potentially impact on albumin uptake and sodium reabsorption. This study demonstrates that consumption of a HFD for 12 weeks reduces renal NHE3 and Na⁺/K⁺‐ATPase expression, an effect that may contribute to the albuminuria associated with obesity. Furthermore the reduction in these transporters is not likely to contribute to the reduced sodium excretion in obesity. These data highlight a potential link between NHE3 and Na⁺/K⁺‐ATPase in the pathophysiological changes in renal protein handling observed in obesity.     

亚慢性铅接触大鼠体内钙调素和腺嘌呤核苷三磷酸酶的影响

大鼠以1.318、5.272和10.545mmol醋酸铅染毒3个月。各染毒组大鼠全血中钙调素(CaM)含量和红细胞膜钙-腺嘌呤核苷三磷酸酶(Ca~(2+)-ATPase)活力显著下降,呈剂量-效应关系。高剂量组红细胞钠-钾-腺嘌呤核苷三磷酸酶(Na~+-K~+-ATPase)活力明显抑制。电镜细胞化学观察,肝细胞腺嘌呤核苷三磷酸酶电子密度变浅、分布减少。     

The effect of high calcium intake on Ca2+ ATPase and the tissue Na:K ratio in spontaneously hypertensive rats

Summary The effects of oral calcium loading on the development of hypertension were studied in spontaneously hypertensive rats (SHR). Forty-eight male SHR were divided into four groups according to treatment: control, calcium, deoxycorticosterone (DOC) and DOC+calcium. Both calcium groups received ad libitum 1.5% CaCl₂ as drinking fluid. The DOC animals were injected with a mineralocorticoid, deoxycorticosterone trimethylacetate, 25 mg/kg, s. c., once a week. Systolic blood pressure (BP) was measured once a week by the tail cuff method. During the nine-week study, the development of hypertension was enhanced in the DOC group, while in the calcium group a blood pressure-lowering effect was observed when compared to the controls. Calcium also abolished the hypertensive effect of DOC. The maximal velocity of calcium transport was higher in insideout-vesicles of red blood cells as compared to controls in both calcium-supplemented groups. DOC treatment resulted in elevated sodium and potassium contents in tail artery tissue, while the effect of the combination of DOC+calcium was equal to controls. On the other hand, the tissue Na:K ratio was decreased in both tail artery wall and heart in the calcium group. Calcium treatment diminished the excretion of phosphate in both groups, while the plasma phosphate concentration was lowered in the calcium group.In mesenteric arterial rings, DOC impaired nitro-prusside-induced relaxation, while the relaxation was enhanced compared to control in both the calcium and DOC+calcium groups.As a summary, it can be assumed that in the calcium group, a higher rate of calcium extrusion via Ca²⁺ ATPase together with a reduction in the tissue Na:K ratio, possibly reflecting a change in Na⁺K⁺ ATPase activity, partially explain the beneficial effects of high calcium intake in blood pressure. The combination DOC+calcium, in turn, seems to oppose the effects of DOC on blood pressure via higher rate of calcium extrusion and by returning the tissue sodium and potassium contents to the control level. Send offprint requests to H. Wuorela at the above address     

玉郎伞水提物对心肌缺血再灌注损伤心肌组织ATP酶和凋亡蛋白的影响

目的:研究玉郎伞水提物(WYLS)对大鼠离体心脏缺血再灌注(I/R)损伤心肌组织Na⁺-K⁺-ATP酶、Ca²⁺-ATP酶和凋亡蛋白的影响。方法:采用Langendorff离体心脏灌流法,停灌30 min再灌30 min建立大鼠心肌缺血再灌注损伤模型。观察WYLS对心肌组织Na⁺-K⁺-ATP酶、Ca²⁺-ATP酶活性的影响、心肌组织病理学变化、凋亡相关蛋白Bcl-2和Bax表达的影响。结果:与I/R组比较,WYLS高剂量组Na⁺-K⁺-ATP酶、Ca²⁺-ATP酶的活性明显增加(P<0.05或P<0.01),心肌受损程度明显减轻(P<0.05)。同时,WYLS高剂量组心肌Bax蛋白表达明显降低(P<0.01),Bcl-2蛋白表达无明显影响(P>0.05),但Bcl-2/Bax的比率明显增加(P<0.05)。结论:WYLS能减轻大鼠心肌I/R损伤,作用机制可能与减轻钙超载、抑制某些凋亡相关蛋白表达有关。     

三硝基甲苯对大鼠肝微粒体Ca^2＋转运的影响

不同浓度的TNT与大鼠肝微粒体在NADPH存在时37℃温育30分钟和60分钟后，微粒体摄取^45Ca有不同程度的抑制，并显示明显的剂量-效应和时间-效应关系，微粒体蛋白巯基含量也降低，且与^45Ca摄取的抑制有明显相关，微粒体用^45Ca预先温育1小时后，TNF可加速^45Ca从微粒体的漏出，亦具有明显的剂量-效应和时间-效应关系。     

利多卡因对家兔心肌缺血／再灌注损伤Na^＋-K^＋-ATPase、Ca^2＋ -Mg^2＋ -ATPase及NO的作用

目的:研究利多卡因对心肌缺血/再灌注损伤家兔心肌Na -K -ATPase、Ca2 -Mg2 -ATPase及血清NO的影响。方法:24只家兔随机分为3组:假手术组(A组)、缺血/再灌注组(B组)、利多卡因组(C组),每组8只。B组、C组阻断左冠状动脉前降支40 min,再灌注90 min,A组仅穿线不结扎。C组于开放冠状动脉再灌注前经颈静脉注射利多卡因5 mg/kg,A、B组注射等量生理盐水。于再灌注90min取颈静脉血测定NO。再灌注90 min后取心肌组织测定NOS、Na -K -ATPase、Ca2 -Mg2 -ATPase。结果:心肌组织Ca2 -Mg2 -ATPaseB组较A、C组降低(P<0.01);Na -K -ATPase B组较A、C组降低(P<0.01);血清NO、心肌组织NOS:B组较A、C组降低(P<0.01)。结论:利多卡因对心肌缺血/再灌注损伤具有保护作用。     

The toxicity of H2O2 on the ionic homeostasis of airway epithelial cells in vitro.

Oxygen species may be formed in the air spaces of the respiratory tract in response to environmental pollution such as particulate matter. The mechanisms and target molecules of these oxidants are still mainly unknown but may involve modifications of the ionic homeostasis in epithelial cells. Cytosolic concentrations of Ca²⁺ (Fura2) and Na⁺ (SBFI) and short-circuit current (Isc) were followed in primary cultures of human nasal epithelial cells and in the cell line 16HBE14o⁻ after exposure to H₂O₂ or ·OH (H₂O₂+Fe²⁺). Cells were grown on glass coverslips for ionic imaging or on permeable snapwell inserts for Isc studies. Exposure of the apical as well as the basal side of the cultures to H₂O₂ or ·OH induced a concentration-dependent transient increase in Isc which is due to a transient secretion of Cl⁻. Ca_i also increased transiently with approximately the same kinetics. The response was dependent on the release of calcium from intracellular stores. Na_i on the contrary increased steadily over more than an hour. When the apical membrane was permeabilized with gramicidin, ·OH inhibited the Na⁺ current (a measure of Na⁺-K⁺-ATPase activity in the baso-lateral membrane). The arrest of the pump was significant after 30 min exposure to oxidant. On the other hand no increase in the apical or baso-lateral sodium conductances could be detected. The progressive arrest of the Na⁺/K⁺-pump may contribute to the sustained elevation of Na_i. This strong modification in the cellular ionic homeostasis may participate in the stress response of the respiratory epithelium through alterations in signal transduction pathways.     

Effects of volume depletion and NaHCO3 loading on the expression of Na+/H+ exchanger isoform 3, Na+: HCO3- cotransporter type 1 and nitric oxide synthase in rat kidney

1. The effects of volume depletion and NaHCO(3) loading on the expression of Na(+)/H(+) exchanger isoform 3 (NHE3), Na(+) : HCO(3)(-) cotransporter type 1 (NBC1) and neuronal (n) and inducible (i) isoforms of nitric oxide synthase (NOS) were determined in rat kidney. 2. Adult male Sprague-Dawley rats were used. Rats were divided into four groups: (i) euvolaemic (EC); (ii) hypovolaemic (HC); (iii) euvolaemia with NaHCO(3) loading (EB); and (iv) hypovolaemia with NaHCO(3) loading (HB). The expression of NHE3, NBC1, nNOS and iNOS proteins was determined in the cortex of the kidney by immunoblotting and immunohistochemistry. Tissue content of nitric oxide (NO) metabolites (NO(x)) were also determined in the cortex using a colourimetric assay. 3. Compared with the EC group, the expression of NHE3 and NBC1 was increased in the HC group and decreased in the EB group. Comparing the EB and HB groups, the expression of NHE3 and NBC1 was higher in the latter group. The expression of NHE3 was decreased and that of NBC1 was increased in the HB group compared with the HC group. The NO(x) content and nNOS expression were decreased in the hypovolaemic (HC) and NaHCO(3)-loaded (EB and HB) rats. Moreover, the expression of iNOS was decreased in the HB group compared with the other groups. 4. An altered volume status and NaHCO(3) loading may affect the regulation of NHE3 and NBC1 in the kidney and the endogenous NO system may play a role in the observed effects.     

白藜芦醇对脊髓损伤后继发性脊髓水肿,乳酸脱氢酶及ATP酶活性的影响

目的　探讨脊髓损伤 (SCI)后使用白藜芦醇 (resvera trol,Res)对继发性脊髓水肿及受损脊髓组织中乳酸脱氢酶(LDH)与Na+ ,K+ ATP酶活性的影响。方法　采用重物下落撞击法制备成年大鼠的脊髓损伤模型 ,于损伤后即刻腹腔注射给予Res 5 0mg·kg-1,10 0mg·kg-1或甲基强的松龙(MPSS) 10 0mg·kg-1,观察给药后 1、2 4、4 8h时Res组受损脊髓组织含水量、LDH及Na+ ,K+ ATP酶活性的变化 ,并与MPSS组进行疗效对比。结果　Res能够明显抑制SCI后继发性水肿 ,以 4 8h为最明显 ,抑制率为 11 5 % ;明显降低LDH活性 ,以 2 4h最大 ,抑制率大于 4 0 % ;明显改善Na+ ,K+ ATP酶活性 ,以 4 8h最显著 ,最大改善率在 6 0 %以上 ,上述作用均与强的松龙相当或更优。结论　Res可以有效抑制脊髓损伤后的水肿及改善能量代谢系统 ,对脊髓损伤有潜在的治疗作用