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1.
目的:评价右旋美托咪定(DEX)后处理对大鼠心肌缺血再灌注时Na+-K+-ATP酶和Ca2+-ATP酶活性的影响。方法:36个成年雄性Wistar大鼠心脏置于改良的Langendoff装置上,均为平衡灌注末HR>180次/min、左室收缩压>75mm Hg、室性早搏<2个/min的心脏模型,采用随机数字表法分为3组:对照组(A组)、缺血再灌注组(B组)、DEX处理组(C组),每组12个。A组持续灌注KH液180 min,B组和C组在KH平衡灌注20 min时常温停灌40 min后恢复灌注,于再灌注即刻分别灌注KH液、含100 nmol·L-1 DEX的KH液20 min,然后继续再灌注KH液100 min。监测心率(HR)、冠状动脉流出量(CF),左心室发展压(LVDP)、左心室内压最大上升和下降速率(±dP/dtmax),采用酶联免疫法测定心肌Na+-K+-ATP酶、Ca2+-ATP酶,以梗死心肌质量占心室质量的百分比表示心肌梗死率。结果:再灌注后A组心功能优于B组、C组(P<0.05),C组优于B组(P<0.05)。与A组比较,B组和C组心肌梗死率较大,心肌组织Na+-K+-ATP酶、Ca2+-ATP酶的活性降低(P<0.05);与B组比较,C组心肌梗死率低,心肌组织Na+-K+-ATP酶、Ca2+-ATP酶的活性较高(P<0.05)。结论:DEX后处理可提高Na+-K+-ATP酶和Ca2+-ATP酶的活性,减轻大鼠心肌缺血再灌注损伤。  相似文献   

2.
Physical-chemical-activity relationship of aromatic hydrocarbons (n = 10) and alkyl acetates (n = 16) with respect to their in vitro effects on synaptosomal membranes was studied. Na+-K+-adenosine triphosphatase (Na+-K+-ATPase) activity and membrane fluidity, which was determined using the fluorescence probe 1,6-diphenyl-1,3,5-hexatriene, were used as potential indicators of neuronal cell toxicity. The potency of inhibition for the enzyme (IC50), the potency of increasing membrane fluidity (IC12.5), and n-octanol/water partition coefficient (P) were all determined experimentally for 26 solvents. Correlation analyses were made on aromatic hydrocarbons and on alkyl acetates. There were linear relationships between log P and pIC50 (log1/IC50) values, and between log P and pIC12.5 (logl/IC12.5) values, indicating that the hydrophobicity of the solvents determines their toxic ability to affect membrane environment; the more hydrophobic the solvents are, the more toxic they are. A direct linear relationship between Na+-K+-ATPase activity pIC50 and membrane fluidity pIC12.5 values was also shown. This predictive correlation suggests a similar mechanism of membrane surface interaction govering both processes that are common to the test solvents. The present results confirm the importance of the lipid environment of neuronal membranes in maintaining the normal function of membrane-bound protein.  相似文献   

3.
目的:研究苦参碱对阿霉素所致H9c2心肌细胞损伤的保护作用及其机制。方法:将H9c2心肌细胞培养,取2~3代细胞进行试验,共分为4组。对照组:接受生理盐水作为干预因素;阿霉素组:接受0.5 mg·L-1阿霉素作为损伤模型;苦参碱+阿霉素组:接受0.5 mg·L-1阿霉素和不同浓度苦参碱(50,150,200 mg·L-1)作为干预因素;苦参碱组:接受不同浓度苦参碱(50,150,200 mg·L-1)作为干预因素。以上各组相应干预24 h后,应用流式细胞仪检测H9c2心肌细胞凋亡水平,应用分光光度法检测线粒体Na+-K+-ATP酶、Ca2+-ATP酶活性,利用JC-1法检测线粒体膜电位。结果:与阿霉素组相比,苦参碱+阿霉素组H9c2心肌细胞凋亡显著减少、线粒体Na+-K+-ATP酶、Ca2+-ATP酶活性显著升高(P<0.05)、线粒体膜电位显著改善。结论:苦参碱对阿霉素所致H9c2心肌细胞有保护作用,减轻心肌细胞凋亡,改善线粒体膜电位、提高线粒体Na+-K+-ATP酶、Ca2+-ATP酶活性。  相似文献   

4.
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。  相似文献   

5.
目的:探讨白藜芦醇对心肌缺血再灌注损伤过程中Ca2+-ATPase及HSP70表达的影响。方法:健康雄性SD大鼠40只,采用随机数字量表法分为4组(假手术组、缺血再灌注组、缺血预适应组、白藜芦醇组),采用结扎冠状动脉前降支制备心肌缺血再灌注损伤模型,于结扎前15 min及再灌注前1 min经舌下静脉注射白藜芦醇10 mg·kg-1。提取心肌线粒体,紫外可见光分光光度计测定线粒体中SDH、Na+-K+-ATPase、Ca2+-ATPase活性;荧光分光光度计测定线粒体中游离钙、mPTP开放度及跨膜电位;RT-PCR及Western blot检测心肌组织HSP70、Ca2+-ATPase mRNA及蛋白质的表达。结果:白藜芦醇与缺血再灌注组及缺血预适应组相比,线粒体中SDH、Na+-K+-ATPase、Ca2+-ATPase的活性明显提高(P<0.05或P<0.01);线粒体内钙离子浓度明显下降(P<0.05或P<0.01)、mPTP开放程度减小(P<0.01)、线粒体膜电位增高(P<0.01);Ca2+-ATPase、HSP70在 mRNA或蛋白水平上的表达均有所增加(P<0.05或P<0.01)。结论:白藜芦醇可能通过增加心肌组织中Ca2+-ATPase、HSP70 mRNA和蛋白的表达,提高线粒体Ca2+-ATPase的活性,产生对大鼠心肌缺血再灌注损伤时线粒体的保护作用。  相似文献   

6.
目的:研究黄芪多糖(APS)对脓毒症急性肾损伤(AKI)大鼠肾上皮细胞能量代谢的影响。方法: 60只大鼠随机抽取10只设为正常组,其余随机分为AKI组,APS低、高剂量组各10只,地塞米松组11只。建模后6,12,18 h时APS低、高剂量组APS 100,200 mg·kg-1灌胃,地塞米松组地塞米松10 mg·kg-1灌胃,正常组及AKI组等量生理盐水灌胃。建模后24 h测磷法检测肾上皮细胞钠-钾-三磷酸腺苷酶(Na-K-ATP)活性;Western blot法检测肾组织沉默信息调节因子2相关酶类1(SIRT1)。结果:与AKI组比较,APS低、高剂量组,地塞米松组Na-K-ATP酶活性增强(t=3.894,P=0.005;t=6.564,P<0.01;t=6.565,P<0.01);与APS低剂量组比较,APS高剂量组、地塞米松组Na-K-ATP酶活性增强(t=2.544,P=0.034;t=2.635,P=0.030);与AKI组比较,APS低、高剂量组,地塞米松组SIRT1蛋白表达量升高(t=9.923,P<0.01;t=12.042,P<0.01;t=10.960,P<0.01);与APS低剂量组比较,APS高剂量组、地塞米松组SIRT1蛋白表达量升高(t=4.985,P=0.001;t=5.000,P=0.001)。结论: APS可改善脓毒症AKI大鼠肾上皮细胞能量代谢,可能与激活AMPK/SIRT1信号通路有关。  相似文献   

7.
目的 探究人参皂苷三醇型与人参皂苷二醇型含量比值变化对大鼠机体的燥性影响.方法 将30只SD大鼠随机分为空白组和4个实验组(R值=0.5、1、1.5、2),每组6只.采用Elisa法测定大鼠血中Na+-K+-ATP酶、Ca2+-Mg2+-ATP酶、乳酸脱氢酶(LDH)、琥珀酸脱氢酶(SDH)以及脑中胆碱酯酶(ChE)、...  相似文献   

8.
目的:研究大黄配伍药后对其泻下作用的变化及其共性关系。方法:将140只实验动物随机分为生理盐水组、果导组及大黄药对组(15 g·kg-1、7.5 g·kg-1,以大黄生药计),按10 mL·kg-1的剂量给药后,分别用代谢笼积分法、酚红糊排空法、炭末推进作用及Na+-K+-ATPase活性实验,比较大黄配伍药对对大鼠的正常泻下作用、酚红糊肠推进功能、炭末推进率及Na+-K+-ATPase活性。结果:大黄与药对配伍后泻下作用均有不同程度的改变,与生理盐水组比较,大黄、大黄牡丹及大黄桃仁15 g·kg-1剂量组显著增加正常小鼠泻下作用、促进肠推进功能、提高炭末推进率及抑制Na+-K+-ATPase活性,表明其泻下作用有显著差异;且与大黄组比较,大黄桃仁及大黄牡丹配伍后的泻下作用有差异,其中泻下作用最显著的是大黄牡丹组。结论:大黄与牡丹、桃仁、甘遂配伍可促进其泻下作用,与枳实、黄连配伍则可抑制其泻下作用,这可能与配伍中药的主要化学成分引起大黄中蒽醌类化合物的溶出量变化及药对间的相使相须作用有关。  相似文献   

9.
Oligomycin inhibits Na+,K+-ATPase activity by stabilizing the Na+ occlusion but not the K+ occlusion. To locate the binding domain of oligomycin on Na+,K+-ATPase, the tryptic-digestion profile of Na+,K+-ATPase was compared with the profile of Na+ occlusion within the digested Na+,K+-ATPase in the presence of oligomycin. The Na+ occlusion profile is responsible for the digestion profile of the -subunit, which is the catalytic subunit of the ATPase. The effect of oligomycin on chimeric Ca2+-ATPase activity was examined. The chimera used, in which the 163 N-terminal amino acids of chicken sarcoplasmic/endoplasmic reticulum Ca2+-ATPase 1 were replaced with the 200 N-terminal amino acids of the chicken Na+,K+-ATPase 1-subunit, partially retains the Na+-dependent characteristics of Na+,K+-ATPase, because the chimeric Ca2+-ATPase activity is activated by Na+ but inhibited by ouabain, a specific inhibitor of Na+,K+-ATPase (Ishii, T., Lemas, M.V., Takeyasu, K., 1994, Proc. Natl. Acad. Sci. U. S. A., 91, 6103–6107). Oligomycin depressed the activation by Na+ of the chimeric Ca2+-ATPase activity. These findings suggest that the 200 N-terminal amino acids of the Na+,K+-ATPase -subunit include a binding domain for oligomycin.  相似文献   

10.
The relationship between progression of neurological status and the activities of both Na+,K+- and Mg2+-dependent-ATPase (adenosine 5′-triphosphate phosphohydrolase) was investigated in brain regions of pyrithiamine-induced thiamine deficient rats. Thalamic Na+,K+-ATPase activity was selectively increased by 200% (P < 0.01) prior to the appearance of symptoms of thiamine deficiency and normalized in symptomatic rats. This selective transitory activation precludes a mediation by brain soluble fraction Na+,K+-ATPase modifiers as does the unaltered distribution in regional high-affinity [3H]ouabain binding densities observed throughout the time-course used in these experiments. Na+,K+-ATPase maintains cellular ionic gradients and has been implicated in neurotransmitter uptake and release mechanisms. The fact that the increased thalamic Na+,K+-ATPase activity coincides with the early alterations in serotonin metabolism observed in similarly treated animals and the concomitantly early increase in glucose utilization previously observed in the thalamus of thiamine-deficient rats is discussed.  相似文献   

11.
In isolated, isometrically contracting left guinea pig atria, sanguinarine, a benzophenanthridine alkaloid from the papaveracea Sanguinaria canadensis, produced a concentration-dependent positive inotropic effect. Between 2.3 × 10−6 M and 6.5 × 10−5 M, sanguinarine increased contractility by 108% which was comparable to the maximal inotropic effect of ouabain. Within the same concentration range, sanguinarine caused inhibition of Na+,K+-ATPase isolated from guinea pig myocardium. 100% inhibition of Na+,K+-ATPase activity occurred at 1 × 10−4 M sanguinarine. The I50 for enzyme inhibition and the ED50 for the inotropic action of sanguinarine were the same (6–6.5 × 10−6 M) indicating that both effects may be causally related.  相似文献   

12.
[(Dihydroindenyl)oxy]acetic acid (DIOA) has been used as a potent inhibitor of K+–Cl cotransporter (IC50 = 10 μM). Here we found that DIOA inhibited activities of P-type ATPases such as dog kidney Na+,K+-ATPase (IC50 = 53 μM), hog gastric H+,K+-ATPase (IC50 = 97 μM) and rabbit muscle Ca2+-ATPase (IC50 = 127 μM). In the membrane preparation of the LLC-PK1 cells stably expressing rabbit gastric H+,K+-ATPase, DIOA inhibited activities of the endogenous Na+,K+-ATPase (IC50 = 95 μM) and the exogenous H+,K+-ATPase (IC50 = 75 μM). 5-Nitro-2-(3-phenylpropylamino)-benzoic acid (NPPB), a Cl channel blocker, had no effects on the DIOA-elicited inhibition of the P-type ATPases. These findings suggest that lower concentration of DIOA (< 20–30 μM) should be used for evaluation of the activity of K+–Cl cotransporter without affecting the activities of coexisting Na+,K+-ATPase and/or H+,K+-ATPase in cells.  相似文献   

13.
ACLMT is a myotoxic Lys49 phospholipase A2 isolated from the venom of the snakeAgkistrodon contortrix laticinctus. We have previously shown that ACLMT increases baseline water transport and partially inhibits vasopressin-stimulated water transport across toad bladders due to an increase in cytosolic calcium. However, these evidences provide insufficient insight into the mechanisms involved in the effects of ACLMT on membrane permeability. In an attempt to better understand such mechanisms, the current study aimed to investigate whether the Na+/K+-ATPase activity of isolated toad bladders can be affected by the ACLMT and the synthetic peptide from its C-terminal region. The toxin significantly decreased the Na+/K+-ATPase, while the peptide did not alter it. These findings suggest that the effects of ACLMT on membrane permeability may be due to the inhibition of the Na+/K+-ATPase activity, and that the C-terminal region may not play a relevant role in this effect. This study contributes toward a better understanding of the mechanisms involved in the toxicity of the snake venom Lys49 PLA2 myotoxins on biological tissues.  相似文献   

14.
The mechanism of interaction between prednisolone-3,20-bisguanylhydrazone (PBGH) and Na+,K+-ATPase (ATP phosphohydrolase, EC 3.6.1.3) was studied using partially purified rat brain enzyme preparations. PBGH inhibited Na+,K+-ATPase rapidly and reversibly. The enzyme-inhibiting action of PBGH was competitively antagonized by potassium. PBGH inhibited Na+, Mg2+ and ATP-supported binding of (3H)-ouabain to the enzyme. When PBGH was added to the incubation mixture at the time when the (3H)-ouabain binding was close to its equilibrium state, the concentration of (3H)-ouabain enzyme complex was rapidly reduced and shifted to a lower equilibrium state. A double reciprocal plot analysis of the (3H)-ouabain binding data indicates that the inhibition of ouabain binding by PBGH is apparently competitive. Binding of (3H)-ouabain in the presence of Tris-phosphate and Mg2+ was also inhibited by unlabeled PBGH. Thus, it appears that the binding of PBGH precludes the bindings of ouabain to Na+,K+-ATPase.  相似文献   

15.
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. Cai also increased transiently with approximately the same kinetics. The response was dependent on the release of calcium from intracellular stores. Nai 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 Nai. This strong modification in the cellular ionic homeostasis may participate in the stress response of the respiratory epithelium through alterations in signal transduction pathways.  相似文献   

16.
目的研究土耳其海绵Ircinia variabilis的化学成分。方法采用多种色谱方法分离纯化,依据理化性质、波谱数据和文献对照的方法鉴定结构。结果从土耳其海绵Ircinia Variabilis提取物中分离鉴定了5个溴代生物碱类化合物:fistularin-3(1),2-oxazolidinone(2),(E)-1-acetamide-3,5-dibromo-4-ethoxy-4-methoxy-1-hydroxy-2,5-cyclohexaddienone(3),(Z)-1-acetamide-3,5-dibromo-4-ethoxy-4-methoxy-1-hydroxy-2,5-cyclohexaddienone(4),3,5-dibromotyrosine(5)。结论化合物1从该种内首次分离得到,化合物2~4从该种属中首次分离得到。  相似文献   

17.
In the synthesis of Moxifloxacin four prominent impurities were detected in HPLC analysis. These impurities were detected in gradient HPLC method. They were isolated from enriched mother liquors and were characterized as 1-cyclopropyl-6-fluoro-1,4-dihydro-8-methoxy-7-[(S,S)-N-methyl-2,8-diazabicyclo (4,3,0) non-8yl]-4-oxo-3-quinoline carboxylic acid (Impurity-1), methyl-1-cyclopropyl-6-fluoro-1,4-dihydro-8-methoxy-7-[(S,S)-2,8-diazabicyclo(4,3,0)non-8-yl]-4-oxo-3-quinoline carboxylate (impurity-2), and 1-cyclopropyl-6-fluoro-1,4 dihydro-8-hydroxy-7-[(S,S)-2,8-diazobicyclo(4,3,0)non-8-yl]-4-oxo-3-quinoline carboxylicacid (impurity-3), 1-cyclopropyl-6,7-difluoro-8-hydroxy-4-oxo-1,4 dihydro-3-quinoline carboxylicacid (impurity-4) by means of 1H, 13C NMR, DEPT, IR and mass spectral data. Structural elucidation by spectral data was discussed.  相似文献   

18.
J. D. Lee  J. C. Shih 《Neuropharmacology》1987,26(12):1667-1671
The effects of SABA ((3-β-(4-azidobenzamidino)ethyl)-5-hydroxyindole), and fluoxetine, on the uptake of 5-hydroxytryptamine (5-HT; serotonin) by cerebral cortical synaptosomes of the rat were studied under normal (147mM) and small (29 mM) concentrations of sodium. In the dark, both compounds competitively inhibited the uptake of 5-HT. However, in the presence of a small concentration of sodium (29 mM), the Ki(nM) for SABA decreased from 128 ± 7 (n = 3) to 93 ± 7 (n = 3) (P < 0.05), whereas the Ki for fluoxetine increased from 30 ± 2 (n = 3) to 59 ± 6 (n = 3) (P < 0.05). The maximum irreversible photoinactivation of the uptake of 5-HT by 1 μM SABA was increased by about 20% when the concentration of sodium ions ([Na+]) was decreased. This is consistent with the Ki data indicating an increase in the affinity of SABA for the uptake site for 5-HT when [Na+] was decreased. The results suggest that there may be two conformational states of the carrier for 5-HT which can be interconverted by changing the concentration of Na+. The affinity of SABA and fluoxetine for these two conformational states is different.  相似文献   

19.
A previous study revealed that a single i.p. administration of 6 mg/kg body wt. of mercuric chloride (MC) durably inhibits the rat cerebral microvascular Na+/K+-ATPase activity [1]. In this study, cerebral microvessels isolated 18 h after MC treatment were compared to those obtained from control rats and subsequently treated or not treated with MC in vitro, with regard to: (a) 3H]ouabain binding to, and (b) K+-activation kinetics of, the Na+/K+-ATPase. Microvessels from MC-treated rats showed a decrease of 3H]ouabain binding down to 62% of the control binding, and the same degree of inhibition was attained in microvessels treated in vitro with 5 μM MC. Analysis of the K+-activation kinetics of Na+/K+-ATPase revealed a decrease of Vmax from the control value of 13.1 to 7.67 μmol/mg/h in microvessels from MC-treated rats and 6.07 μmol/mg/h in microvessels treated in vitro with 5 μM MC, with no change in Km in either case. The similarity of the effects of in vivo and in vitro treatments suggests that the inhibition of the cerebromicrovascular Na+/K+ATPase following in vivo administration of MC results from a direct interaction of Hg+ with the enzyme.  相似文献   

20.
Luo Y  Zhou M  Qi H  Li B  Zhang G 《Planta medica》2005,71(11):1081-1084
Three new compounds, goldfussins A (1) and B (2) and goldfussinol (3), and sixteen known compounds were isolated from the ethanolic extract of the whole plants of Goldfussia psilostachys. The structures of the new compounds were elucidated as a novel cadinane sesquiterpene, 1,8-dimethyl-5-hydroxymethyl-9-oxo-6,7,8,9-tetrahydronaphtho[2,1- b]furan (1), a novel norcadinane sesquiterpene, 4-acetyl-3-hydroxy-1-hydroxymethyl-6-methyl-5-oxo-5,6,7,8-tetrahydronaphthalene (2) and methyl 3-hydroxy-2-(3,5-dimethoxy-4-hydroxyphenyl)-propanoate (3) on the basis of spectral data.  相似文献   

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