Assessing the growth of Arctic charr (Salvelinus alpinus) (Linnaeus, 1758) in four salinities, under experimental conditions / Avaliando o crescimento do Charr Ártico (Salvelinus alpinus) (Linnaeus, 1758) em quatro salinidades, sob condições experimentais

Abstract Studies in Salvelinus alpinus, Arctic charr, indicate that it has a low capacity to hyposmorregulatory or adaption to sea in winter periods in Arctic waters. The investigation finds to determinate the rank optimum of salinity to can cultivate this species at Chile. The weight adequate was determined to join on the sea by analysis of gill Na+, K+-ATPase activity, that it was found between the ranks 80-130 g, with 14.5 U/mg. It underwent evaluation of fish growth of 72 g salinities from 0 (control), 18, 25 and 33 g/L (sea water) for 94 days. The results indicate that the largest increases were obtained in brackish water. T18 g/L and T25 g/L achieved growth of 25% and 19% on day 94 and term sampling respectively. It is important to mention that the 8% that survived in seawater introduced percentages growth 16.6% equivalent to brackish water and control. These results suggest that Salvelinus alpinus can grow in seawater, with levels of Na+, K+-ATPase similar to those submitted by Salmo salar with a weight not less than 80 g.

Resumo Estudos em Salvelinus alpinus, Charr Ártico, indicam que tem baixa capacidade de hiposmorregulação ou adaptação ao mar em períodos de inverno nas águas do Ártico. A investigação determina o melhor nível de salinidade para cultivar esta espécie no Chile. Determinou-se o peso adequado para se unir ao mar pela análise da atividade da Na +, K + -ATPase das brânquias, que foi encontrada entre as faixas de 80 a 130 g, com 14,5 U/mg. Foi avaliado o crescimento de 72 g salinidades de 0 (controle), 18, 25 e 33 g/L (água do mar) por 94 dias. Os resultados indicam que os maiores aumentos foram obtidos em água salobra. T18 g/L e T25 g/L alcançaram crescimento de 25% e 19% no dia 94 e amostragem a termo, respectivamente. É importante mencionar que os 8% que sobreviveram na água do mar apresentaram percentuais de crescimento de 16,6% equivalentes a água salobra e controle. Estes resultados sugerem que o Salvelinus alpinus pode crescer em água do mar, com níveis de Na +, K + -ATPase semelhantes aos apresentados por Salmo salar com um peso não inferior a 80 g.

Inhibition of curcumin derivative C1209 on proliferation of CML cells by disrupting Hsp90 chaperon function / 中国药理学通报

Aim To estimate the inhibition of curcumin derivative C1209 on the proliferation of chronic myeloid leukemia (CML) cells involving the disruption Hsp90 chaperon function. Methods The fluorescence spec-trum experiment was applied to examine the affinity be-tween different C1209 concentrations and Hsp90, NH-sp90,MHsp90,CHsp90;fluorescence intensities were recorded in the range of 290~510 nm at 293 K,303 K and 310 K,respectively;a colorimetric assay for in-organic phosphate based on the formation of a phospho-molybdate complex and subsequent reaction with mala-chite green was used to examine the inhibitory effects of C1209 on the activity of Hsp90 ATPase. MTT assay and CFSE were used for K562 and K562/G01cell pro-liferation determination in vitro by C1209. Western blot was used to detect the client proteins and the mo-lecular chaperone of Hsp90 level. Results The disso-ciation constant KDvalues of C1209 was (14.733 ± 0.713) μmol·L-1. The interaction between C1209 and Hsp90 was driven mainly by electrostatic interac-tion. C1209 showed the strongest affinity with CHsp90. When the concentration of ATP was 1mmol· L-1,the inhibition of Hsp90 ATPase activity of C1209 with the IC50value was 11.4 μmol·L-1; C1209 showed inhibition of K562 and K562/G01cells in dose-dependent proliferation and the IC50value was 1.14 μmol·L-1and 0.56 μmol·L-1, respectively after 24 h incubation. C1209 affected the molecular chaper-one functions of Hsp90 and down-regulated Bcr-Abl, Akt, MEK, ERK, c-Raf, p-Akt, p-MEK and p-ERK protein levels which were client proteins of Hsp90 in K562 and K562/G01cells. Conclusions Curcumin derivative C1209 is Hsp90 inhibitor;C1209 has signif-icant inhibitory effects on proliferation of K562 and K562 / G01, which may be related to C1209 affecting the molecular chaperone functions of Hsp90 and down-regulating client proteins of Hsp90 level.

Assessing the growth of Arctic charr (Salvelinus alpinus) (Linnaeus, 1758) in four salinities, under experimental conditions

Abstract Studies in Salvelinus alpinus, Arctic charr, indicate that it has a low capacity to hyposmorregulatory or adaption to sea in winter periods in Arctic waters. The investigation finds to determinate the rank optimum of salinity to can cultivate this species at Chile. The weight adequate was determined to join on the sea by analysis of gill Na+, K+-ATPase activity, that it was found between the ranks 80-130 g, with 14.5 U/mg. It underwent evaluation of fish growth of 72 g salinities from 0 (control), 18, 25 and 33 g/L (sea water) for 94 days. The results indicate that the largest increases were obtained in brackish water. T18 g/L and T25 g/L achieved growth of 25% and 19% on day 94 and term sampling respectively. It is important to mention that the 8% that survived in seawater introduced percentages growth 16.6% equivalent to brackish water and control. These results suggest that Salvelinus alpinus can grow in seawater, with levels of Na+, K+-ATPase similar to those submitted by Salmo salar with a weight not less than 80 g.

Resumo Estudos em Salvelinus alpinus, Charr Ártico, indicam que tem baixa capacidade de hiposmorregulação ou adaptação ao mar em períodos de inverno nas águas do Ártico. A investigação determina o melhor nível de salinidade para cultivar esta espécie no Chile. Determinou-se o peso adequado para se unir ao mar pela análise da atividade da Na +, K + -ATPase das brânquias, que foi encontrada entre as faixas de 80 a 130 g, com 14,5 U/mg. Foi avaliado o crescimento de 72 g salinidades de 0 (controle), 18, 25 e 33 g/L (água do mar) por 94 dias. Os resultados indicam que os maiores aumentos foram obtidos em água salobra. T18 g/L e T25 g/L alcançaram crescimento de 25% e 19% no dia 94 e amostragem a termo, respectivamente. É importante mencionar que os 8% que sobreviveram na água do mar apresentaram percentuais de crescimento de 16,6% equivalentes a água salobra e controle. Estes resultados sugerem que o Salvelinus alpinus pode crescer em água do mar, com níveis de Na +, K + -ATPase semelhantes aos apresentados por Salmo salar com um peso não inferior a 80 g.

C0818, a novel curcumin derivative, interacts with Hsp90 and inhibits Hsp90 ATPase activity

The aims of the present study were to estimate the affinity between 3,5-()-bis(3-methoxy-4-hydroxybenzal)-4-piperidinone hydrochloride (C0818) and heat shock protein 90 (Hsp90) and to investigate the inhibitory effects of this compound on Hsp90 ATPase activity. Fluorescence spectroscopy was used to examine the affinity between varying concentrations of C0818 and Hsp90, N-Hsp90, M-Hsp90 and C-Hsp90. Fluorescence intensities were recorded in the range of 290-510 nm at 293, 303 and 310 K, respectively. A colorimetric assay for inorganic phosphate (based on the formation of a phosphomolybdate complex and the subsequent reaction with malachite green) were used to examine the inhibitory effects of C0818 on Hsp90 ATPase activity. The equilibrium dissociation constantvalue of C0818 was found to be 23.412±0.943 μmol/L. The interaction between C0818 and Hsp90 was driven mainly by electrostatic interactions. C0818 showed the strongest affinity with C-Hsp90. These results conclusively demonstrate the inhibitory activity of C0818 on the activity of Hsp90 ATPase.

An optimized micro-assay of myosin II ATPase activity based on the molybdenum blue method and its application in screening natural product inhibitors / 中国天然药物

Myosin II plays multiple roles in physiological and pathological functions through its ATPase activity. The present study was designed to optimize a micro-assay of myosin II ATPase activity based on molybdenum blue method, using a known myosin II ATPase inhibitor, blebbistatin. Several parameters were observed in the enzymatic reaction procedure, including the concentrations of the substrate (ATP) and calcium chloride, pH, and the reaction and incubation times. The proportion of coloration agent was also investigated. The sensitivity of this assay was compared with the malachite green method and bioluminescence method. Additionally, 20 natural compounds were studied for myosin II ATPase inhibitory activity using the optimized method. Our results showed that ATP at the concentration of 5 mmol·L(-1) and ammonium molybdate : stannous chloride at the ratio of 15 : 1 could greatly improve the sensitivity of this method. The IC50 of blebbistatin obtained by this method was consistent with literature. Compound 8 was screened with inhibitory activity on myosin II ATPase. The optimized method showed similar accuracy, lower detecting limit, and wider linear range, which could be a promising approach to screening myosin II ATPase inhibitors in vitro.

Effects of Four Interior-warming Drugs on the Tension of Ileum Smooth Muscle and Ca2+-ATPase in Rabbits / 医药导报

Objective To investigate the effects of four interior-warming drugs( galangal,cinnamon,evodia rutaecarpa,and dried ginger)on the tension of ileum smooth muscle and Ca2+-ATPase on the cell membrane in rabbits. Methods The effects of galangal,cinnamon,evodia rutaecarpa,and dried ginger were examined on normal ileum smooth muscle,in vitro intestinal muscle contraction caused by acetylcholine(ACh),barium chloride(BaCl2 )and histamine(His), and ACh-induced calcium release by using BL-420E+ biological signal collection and processing system.The average tension was measured within 1 min before delivery and within 3 minutes after the treatment,and the inhibition rate was calculated according to the average tension value.The effects of sera containing galangal,cinnamon,evodia rutaecarpa,and dried ginger on Ca2+-ATPase activity on the cell membrane of the intestinal smooth muscle were examined by phosphorus method. Results Galangal,cinnamon,evodia rutaecarpa,and dried ginger at high concentrations could restrain in vitro intestinal contraction in normal circumstances(P<0.05 or P<0.01).Significant inhibitory effects on intestinal contraction caused by ACh,His and BaCl2 were found in low,medium and high concentration groups(P<0.01).There was a dose-effectiveness relationship between the inhibition rate and final drug concentrations.The ACh-induced intracellular and extracellular calcium dependent contraction were significantly inhibited by the four interior-warming drugs( P < 0. 05 or P < 0. 01). The Ca2+-ATPase activities were( 0. 384 ± 0.070),(0.302±0.016),(0.307±0.016),(0.296±0.016),(0.313±0.003)U·mg-1 ,respectively,in intestinal smooth muscle in normal control group and high concentration groups of galangal,cinnamon,evodia rutaecarpa,and dried ginger(P<0.01). Conclusion Interior-warming drugs may relax intestinal smooth muscle by reducing the intracellular calcium release and the extracellular calcium inflow via receptor-controlled calcium channels,and inhibiting the Ca2+-ATPase activity in smooth muscle.

Synergic actions of polyphenols and cyanogens of peanut seed coat (Arachis hypogaea) on cytological, biochemical and functional changes in thyroid.

In animals, long-term feeding with peanut (Arachis hypogaea) seed coats causes hypertrophy and hyperplasia of the thyroid gland. However, to date there have been no detailed studies. Here, we explored the thyroidal effects of dietary peanut seed coats (PSC) in rats. The PSC has high levels of pro-goitrogenic substances including phenolic and other cyanogenic constituents. The PSC was mixed with a standard diet and fed to rats for 30 and 60 days, respectively. Animals fed with the PSC-supplemented diet showed a significant increase in urinary excretion of thiocyanate and iodine, thyroid enlargement, and hypertrophy and/or hyperplasia of thyroid follicles. In addition, there was inhibition of thyroid peroxidase (TPO) activity, 5’-deiodinase-I (DIO1) activity, and (Na+-K+)-ATPase activity in the experimental groups of rats as compared to controls. Furthermore, the PSC fed animals exhibited decreased serum circulating total T4 and T3 levels, severe in the group treated for longer duration. These data indicate that PSC could be a novel disruptor of thyroid function, due to synergistic actions of phenolic as well as cyanogenic constituents.

Effect of Apple (Malus domestica) on Na+/K+-ATPase Activity in Liver, kidney and Heart of Adult Wistar Rats.

Aim: The effect of crude extract of apple on the activity of Na+/K+-ATPase in the liver, kidney and heart tissues of rats was investigated. Methodology: Two separate test groups of animals were fed a standard laboratory diet, water and given 1 ml and 1.5 ml/ kg body weight of crude extract of apple respectively. The control animals were fed the diet and water. The animals were treated for 6 weeks and then sacrificed. The liver, kidney and heart were excised from the rats and subsequently used for analysis of Na+/K+-ATPase. Results: The results obtained indicate that there was no significant (p>0.05) change in body weights of rats administered 1 ml and 1.5 ml/ kg body weight of apple extract. Similarly no significant (P>0.05) change was observed in the weight of liver, kidney and heart of test rats relative to control. Examination of the data reveal that the activity of the enzyme was significantly (P<0.05) decreased in the kidney but not in the liver and heart of the rats treated with the extract as compared to control. The renal Na+/K+-ATPase activity was lowest in rats treated with an extract dose of 1.5 ml / kg body weight of extract. Conclusion: The present study has shown that the Na+/K+-ATPase activity in the kidney was inhibited by apple extract. The inhibition of the enzyme is suspected to be due to some phytochemicals present in apple. However, this suggestion remains to be scientifically confirmed.

On Brain targeting research of ginkgolide B prodrug / 中国药理学通报

Aim To investigate the brain targeting of ginkgolide B prodrug (PGB ) and its mechanism. Methods The liquid chromatography tandem mass spectrometry (LC-MS /MS)method was applied to in-vestigate the pharmacokinetics of PGB in rat brain tis-sue after intravenous injection of PGB.Also the brain targeting was evaluated on the basis of the pharmacoki-netic parameter of PGB.The incomplete cerebral is-chemia model was induced in mouse,the effect of PGB on cerebral capillary permeability was observed by Ev-ans blue method.High performance liquid chromatog-raphy (HPLC)was used to determine the partition co-efficients (logP)of PGB in octanol-water system.PGB and P-glycoprotein (P-gp)was docked by using Mole-gro Virtual Docker (MVD)software to predict its bind-ing abilities with P-gp.The interaction of PGB with ATPase activity of human P-gp membrane was esti-mated by measuring inorganic phosphate liberation. Results The brain targeting of PGB was evaluated by treatment effective (TA ) and drug targeting index (DTI),the calculated value were 6.87 and 4.1 4 re-spectively.Preventive medication of PGB could signifi-cantly decrease cerebral capillary permeability (P <0.05).The lipo-hydropartition coefficient of PGB was higher than that of GB,their logP data were 1 .03 and 0.61 respectively.PGB displayed the stronger binding affinity with P-gp than GB according to the molecular docking calculations,their MolDock Score toward P-gp were -1 43.36 and -1 1 6.40KJ·mol -1 respectively. ATP-hydrolisis showed that PGB increased ATPase activity with a Km of approximately 237.75 μmol · L -1 ,however GB with a Km of approximately 841 .24μmol·L -1 .PGB might interact with P-gp with a high-er affinity and exhibit more effect than GB.Conclu-sion PGB is characterized by its brain targeting. Higher liposolubility of PGB results in good blood-brain permeability,which is advantageous to its brain targe-ting.Besides,PGB can effectively inhibit the efflux effect of P-gp to GB because of its increased P-gp AT-Pase activity.

Standardization of metachromatic staining method of myofibrillar ATPase activity of myosin to skeletal striated muscle of mules and donkeys / Padronização do método de coloração metacromático da atividade da miosina ATPase miofibrilar para músculo estriado esquelético de muares e asininos

This study aims at standardizing the pre-incubation and incubation pH and temperature used in the metachromatic staining method of myofibrillar ATPase activity of myosin (mATPase) used for asses and mules. Twenty four donkeys and 10 mules, seven females and three males, were used in the study. From each animal, fragments from the Gluteus medius muscle were collected and percutaneous muscle biopsy was performed using a 6.0-mm Bergstrõm-type needle. In addition to the metachromatic staining method of mATPase, the technique of nicotinamide adenine dinucleotide tetrazolium reductase (NADH-TR) was also performed to confirm the histochemical data. The histochemical result of mATPase for acidic pre-incubation (pH=4.50) and alkaline incubation (pH=10.50), at a temperature of 37ºC, yielded the best differentiation of fibers stained with toluidine blue. Muscle fibers were identified according to the following colors: type I (oxidative, light blue), type IIA (oxidative-glycolytic, intermediate blue) and type IIX (glycolytic, dark blue). There are no reports in the literature regarding the characterization and distribution of different types of muscle fibers used by donkeys and mules when performing traction work, cargo transportation, endurance sports (horseback riding) and marching competitions. Therefore, this study is the first report on the standardization of the mATPase technique for donkeys and mules...

O presente estudo objetivou padronizar o pH e a temperatura da pré-incubação e incubação do método de coloração metacromática de myofibrillar atividade ATPase da miosina (mATPase) utilizada para asininos e muares. Vinte e quatro jumentos e 10 muares, sete machos e três fêmeas, foram usados no estudo. De cada animal, fragmentos do músculo Gluteus medius foram coletados e biópsia muscular percutânea foi realizada por meio de uma agulha Bergstrõm tipo de 6,0 mm. Em adição ao método de coloração metacromática de mATPase, a técnica de nicotinamida adenina dinucleótido tetrazólio redutase (NADH-TR) foi também realizada para confirmar os dados histoquímicos. O resultado histoquímico da mATPase por pré-incubação ácida (pH=4,50) e incubação alcalina (pH=10,50), a uma temperatura de 37ºC, foi o que proporcionou a melhor diferenciação das fibras coradas com azul de toluidina. As fibras musculares foram identificadas de acordo com as seguintes cores: tipo I (oxidativa, azul claro), tipo IIA (oxidativo-glicolítico, azul intermediário) e tipo IIX (glycolytic, azul escuro). Na literatura, não foram encontradas publicações pertinentes à caracterização e distribuição dos diferentes tipos de fibras musculares utilizadas pelos asininos e muares nos trabalhos de tração, no transporte de cargas, em provas esportivas de resistência (cavalgadas) e concursos de marcha. Dessa forma, essa pesquisa é o primeiro relato sobre padronização da técnica de mATPase para muares e asininos...

Evaluation of Na+, K+-ATPase activity in the brain of young rats after acute administration of fenproporex

Objectives: Fenproporex is an amphetamine-based anorectic which is rapidly converted into amphetamine in vivo. Na+, K+-ATPase is a membrane-bound enzyme necessary to maintain neuronal excitability. Considering that the effects of fenproporex on brain metabolism are poorly known and that Na+, K+-ATPase is essential for normal brain function, this study sought to evaluate the effect of this drug on Na+, K+-ATPase activity in the hippocampus, hypothalamus, prefrontal cortex, and striatum of young rats. Methods: Young male Wistar rats received a single injection of fenproporex (6.25, 12.5, or 25 mg/kg intraperitoneally) or polysorbate 80 (control group). Two hours after the last injection, the rats were killed by decapitation and the brain was removed for evaluation of Na+, K+-ATPase activity. Results: Fenproporex decreased Na+, K+-ATPase activity in the striatum of young rats at doses of 6.25, 12.5, and 25 mg/kg and increased enzyme activity in the hypothalamus at the same doses. Na+, K+-ATPase activity was not affected in the hippocampus or prefrontal cortex. Conclusion: Fenproporex administration decreased Na+, K+-ATPase activity in the striatum even in low doses. However, in the hypothalamus, Na+, K+-ATPase activity was increased. Changes in this enzyme might be the result of the effects of fenproporex on neuronal excitability. .

Curcumin restores mitochondrial functions and decreases lipid peroxidation in liver and kidneys of diabetic db/db mice

BACKGROUND: Nitrosative and oxidative stress play a key role in obesity and diabetes-related mitochondrial dysfunction. The objective was to investigate the effect of curcumin treatment on state 3 and 4 oxygen consumption, nitric oxide (NO) synthesis, ATPase activity and lipid oxidation in mitochondria isolated from liver and kidneys of diabetic db/db mice. RESULTS: Hyperglycaemia increased oxygen consumption and decreased NO synthesis in liver mitochondria isolated from diabetic mice relative to the control mice. In kidney mitochondria, hyperglycaemia increased state 3 oxygen consumption and thiobarbituric acid-reactive substances (TBARS) levels in diabetic mice relative to control mice. Interestingly, treating db/db mice with curcumin improved or restored these parameters to normal levels; also curcumin increased liver mitochondrial ATPase activity in db/db mice relative to untreated db/db mice. CONCLUSIONS: These findings suggest that hyperglycaemia modifies oxygen consumption rate, NO synthesis and increases TBARS levels in mitochondria from the liver and kidneys of diabetic mice, whereas curcumin may have a protective role against these alterations.

Interactions study between C0817 and Hsp90 by fluorescence spectrometry / 中国药学杂志

OBJECTIVE: To estimate the interaction between C0817 and Hsp90 and the inhibitory effects C0817 on the activity Hsp90 ATPase. METHODS: The fluorescent spectrometry method was applied to examine the affinity between different concentrations C0817 and Hsp90; fluorescence intensities were recorded in the range 290-510 nm at 293 K, 303 K and 310 K, respectively; colori-metric assay for inorganic phosphate based on the formation a phosphomolybdate complex and subsequent reaction with malachite green was used to examine the inhibitory effects C0817 on the activity Hsp90 ATPase. RESULTS: The dissociation constant KD value C0817 was (24.740 ± 1.752) μmol · L-1. The interaction between C0817 and Hsp90 was driven mainly by electrostatic interaction. When the concentration ATP was 1 mmol · L-1, C0817 could not inhibit the ATPase activity Hsp90. CONCLUSION: The interaction mechanism between C0817 and Hsp90 can be analyzed by fluorescence spectrum. C0817 doesn't show inhibitory action for ATPase Hsp90.

Dynamic studies on photosynthetic characteristics and growth development of Perilla frutescens / 中草药

Objective: To provide basic theory for rational cultivation and comprehensive utilization of Perilla frutescens. Methods: The photosynthesis and growth characteristics were measured every 25 d from July 10th, 2013. Results: Logistic equation of dry matter weight was firstly established, and the slightly increasing stage was also called seedling stage (0-75 d); The flower budding stage was 76-84 d, the blooming stage was 85-95 d, and the 20 d was called period of accelerating growth stage; The period of decelerating growth was defoliation period (96-125 d). As was observed both specimens "a" and "b", chlorophyll content increased and reached the peak value during flower budding before going on a gradual decline, but not before that of soluble proteins. The Hill reaction, as well as Ca2+-ATPase and Mg2+-ATPase activities all reached the peak values just before blooming began; The photosynthesis rate was at peak twice during seedling stage, which was once more than in any other stage of the growth of Perilla frutescens. Strong positive correlation was observed between stomatal conductance and transpiration rate. Conclusion: For maximum yield of leaf, stem, or seed, harvesting should take place either before flowers bloom or after leaves fall. All growth-spurring measures should be implemented before growth rate reaches a zenith or risk not being effective.

Interactions between curcumin derivatives C085 and various constructs of Hsp90 and effects of C085 on Hsp90 ATPase activity / 中国药理学通报

Aim To estimate the affinity between C085 and Hsp90 and the inhibitory effects of C085 on the activity of Hsp90 ATPase. Methods The fluores-cence spectrum experiment was applied to examine the affinity between different C085 concentrations and Hsp90 , NHsp90 , MHsp90 , CHsp90; fluorescence in-tensities were recorded in the range of 290-510 nm at 293 K, 303 K and 310 K, respectively;a colorimetric assay for inorganic phosphate based on the formation of a phosphomolybdate complex and subsequent reaction with malachite green was used to examine the inhibitory effects of C085 on the activity of Hsp90 ATPase. Re-sults The dissociation constant KD value of C085 was (11. 163 ± 0. 316 ) μmol · L-1 . The interaction be-tween C085 and Hsp90 was driven mainly by electro-static interaction. C085 showed strongest affinity with CHsp90. When the concentration of ATP was 1 mmol· L-1 ,the inhibition of Hsp90 ATPase activity of C085 with the IC50 value was 6. 04μmol·L-1 . Conclusions The interaction mechanism between C085 and Hsp90 can be analyzed by fluorescence spectrum. C085 shows strong inhibition ATPase activity of Hsp90 .

Protective effect of some amino acids synthesized derivatives and their chelates on Escherichia coli under X-ray irradiation.

The protective effects of novel synthesized derivatives of some amino acids — nicotinyl-L-tyrosinate and nicotinyl-L-tryptophanate schiff bases and their Cu(II) and Mn(II) chelates on growth, survival and membrane-associated ATPase activity of E. coli under X-ray irradiation were investigated. The specific growth rate and survival of E. coli were decreased at 10, 20 and 30 Gy doses. However, as 30 Gy was found to be the most effective irradiation dose, it was chosen for studying the radio-protective properties of different compounds. These compounds could increase the bacterial cell protection against X-ray irradiation in concentration-dependent manner. They had a role in stimulation of synthesis or regulation of activity of metal-dependent enzymes, required for reversing the X-ray irradiation damage. The study may prove useful for further estimation of the effectiveness of different compounds as radio-protectors on bacteria and other cells, especially mammalian cells under X-ray irradiation.

Lead reduces tension development and the myosin ATPase activity of the rat right ventricular myocardium

Lead (Pb2+) poisoning causes hypertension, but little is known regarding its acute effects on cardiac contractility. To evaluate these effects, force was measured in right ventricular strips that were contracting isometrically in 45 male Wistar rats (250-300 g) before and after the addition of increasing concentrations of lead acetate (3, 7, 10, 30, 70, 100, and 300 µM) to the bath. Changes in rate of stimulation (0.1-1.5 Hz), relative potentiation after pauses of 15, 30, and 60 s, effect of Ca2+ concentration (0.62, 1.25, and 2.5 mM), and the effect of isoproterenol (20 ng/mL) were determined before and after the addition of 100 µM Pb2+. Effects on contractile proteins were evaluated after caffeine treatment using tetanic stimulation (10 Hz) and measuring the activity of the myosin ATPase. Pb2+ produced concentration-dependent force reduction, significant at concentrations greater than 30 µM. The force developed in response to increasing rates of stimulation became smaller at 0.5 and 0.8 Hz. Relative potentiation increased after 100 µM Pb2+ treatment. Extracellular Ca2+ increment and isoproterenol administration increased force development but after 100 µM Pb2+ treatment the force was significantly reduced suggesting an effect of the metal on the sarcolemmal Ca2+ influx. Concentration of 100 µM Pb2+ also reduced the peak and plateau force of tetanic contractions and reduced the activity of the myosin ATPase. Results showed that acute Pb2+ administration, although not affecting the sarcoplasmic reticulum activity, produces a concentration-dependent negative inotropic effect and reduces myosin ATPase activity. Results suggest that acute lead administration reduced myocardial contractility by reducing sarcolemmal calcium influx and the myosin ATPase activity. These results also suggest that lead exposure is hazardous and has toxicological consequences affecting cardiac muscle.

Study on erythrocyte ATPase activity in patients with generalized tonic clonic epilepsy of different frequence seizure / 临床神经病学杂志

Objective To study the relationship between generalized tonic clonic epilepsy of different frequence seizure and erythrocyte ATPase activity.Methods We measured Na +/K + ATPase,Mg 2+ ATPase,Ca 2+ ATPase activity of 68 patients with generalized tonic clonic seizure who were divided into 3 groups by different frequence:Status epilepsy group (SE) for 26 cases,Frequency epilepsy (FE) group for 22 cases,epilepsy (EP) group for 20 cases and the normal controls for 35 cases.Results Erythrocyte Na +/K + ATPase in SE, FE group decreased,as compared with EP group,the normal control group, there was remar kable difference( P

Quantitative Measurement of Membrane Na+-K+ ATPase Activity using Thallium-201: Comparison with Rubidium-86 / 대한핵의학회잡지

PURPOSE: Na+-K+ ATPase Activity has beem estimated by the degree of inhibition of cation transport by cardiac glycosides (ouabain) using Rb-86 as a substrate. The biological characterist-Isc of T1-201 is known to be simiIar to those of potassium as a transport substrate in the presence of glucose, insulin or phobol myristate acetate (PMA). The purpose of this study was to measure ouabain sensitive Na+-K+ ATPase activity using T1-201 and compare with that using Rb-86. MATERIALS AND METHODS: Smooth muscle cells isolated from rat aorta or human placental umbilical artery were cultured, and used to measure cellular Na+-K+ ATPase activity. Na+-K+ ATPase activity was measured as a percentage decrease in cellular uptake of T1-201 or Rb-86 by ouabain under the presence of glucose, insulin or PMA in media. RESULTS: Na+-K+ ATPase ase activity measured with T1-201, as a transport substrate, was not different from those measured with Rb-86 in rat or human smooth muscle cell preparation. Incubation with high concentration glucose resulted in about 30% decrease in enzyme activity. In contrast, insulin or PMA resulted in 50-70% or 28% increases from baseline activity, respectively. CONCLUSION: These results suggests that T1-201 could replace Rb-86 in measurement of ouabain sensititive Na+-K+ ATPase activity in vitro. High level of glucose concentration decreased cellular Na+-K+ ATPase activity, but insulin or PMA increased it.

Effect of t-butylhydroperoxide on Na+/-dependent glutamate uptake in rabbit brain synaptosome

The effect of an organic peroxide, t-butylhydroperoxide (t-BHP), on glutamate uptake was studied in synaptosomes prepared from cerebral cortex. t-BHP inhibited the Na+/-dependent glutamate uptake with no change in the Na+/-independent uptake. This effect of t-BHP was not altered by addition of Ca2+ channel blockers (verapamil, diltiazem and nifedipine) or PLA2 inhibitors (dibucaine, butacaine and quinacrine). However, the effect was prevented by iron chelators (deferoxamine and phenanthroline) and phenolic antioxidants (N,N'-diphenyl-phenylenediamine, butylated hydroxyanisole, and butylated hydroxytoluene). At low concentrations (< 1.0 mM), t-BHP inhibited glutamate uptake without altering lipid peroxidation. Moreover, a large increase in lipid peroxidation by ascorbate/Fe2+ was not accompanied by an inhibition of glutamate uptake. The impairment of glutamate uptake by t-BHP was not intimately related to the change in Na+/-K+/-ATPase activity. These results suggest that inhibition of glutamate uptake by t-BHP is not totally mediated by peroxidation of membrane lipid, but is associated with direct interactions of glutamate transport proteins with t-BHP metabolites. The Ca2+ influx through Ca2+ channel or PLA2 activation may not be involved in the t-BHP inhibition of glutamate transport.