Change in malate dehydrogenase and alpha amylase activities in Rubus fruticosus and Valeriana jatamansi treated granary weevil, Sitophilus granarius / Mudança nas atividades de malato desidrogenase e alfa amilase em Rubus fruticosus e gorgulho tratado com Valeriana jatamansi, Sitophilus granarius

Poor storage conditions provide favorable environment to stored grain pests for their growth. The bio-pesticides are the best alternatives to synthetic pesticides. Present study was conducted to compare toxicity of Rubus fruticosus and Valeriana jatamansi against granary weevil, Sitophilus granarius and subsequent changes in enzyme activity responsible for grain damage. In current research 5 g of R. fruticosus fruit and V. jatamansi rhizome powders were tested separately against S. granarius, in 50 g wheat whole grains for seven days in comparison with the control. The enzymatic activity of malate dehydrogenase and α-amylase was observed in the cellular extracts of S. granarius. The insects were crushed and homogenized in phosphate-buffer solution and centrifuged at 10000 rpm for 5 minutes. For the enzymatic measurement supernatant was tested; the spectrophotometer was adjusted at 340 nm. The reagents were mixed and incubated at 25 °C for five minutes. The cuvettes were placed in the experimental and reference sites of spectrophotometer and recorded the change in absorbance for 3-4 minutes. There was 5.60% and 14.92% reduction in the activity of malate dehydrogenase in R. fruticosus and V. jatamansi, treated insects, respectively. The alpha amylase enzyme activity was 6.82% reduced and 63.63% increase in R. fruticosus and V. jatamansi, treated insects, respectively. Present study addresses that both plant powders are effective against granary weevil by altering enzyme activities so both the plant powders can be used as bio-pesticides against the stored grains pests.

As más condições de armazenamento proporcionam um ambiente favorável às pragas armazenadas para o crescimento. Os biopesticidas são as melhores alternativas aos pesticidas sintéticos. O presente estudo foi conduzido para comparar a toxicidade de Rubus fruticosus e Valeriana jatamansi contra gorgulhos, Sitophilus granarius e subsequentes alterações na atividade enzimática responsáveis ​​por danos aos grãos. Na pesquisa atual, 5 g de frutos de R. fruticosus e pós de rizoma de V. jatamansi foram testados separadamente contra S. granarius, em 50 g de grãos integrais de trigo por sete dias, em comparação com o controle. A atividade enzimática da malato desidrogenase e α-amilase foi observada nos extratos celulares de S. granarius. Os insetos foram esmagados e homogeneizados em solução tampão fosfato e centrifugados a 10000 rpm por 5 minutos. Para a medição enzimática, o sobrenadante foi testado; o espectrofotômetro foi ajustado a 340 nm. Os reagentes foram misturados e incubados a 25 °C por cinco minutos. As cubetas foram colocadas nos locais experimentais e de referência do espectrofotômetro e registradas as alterações na absorbância por 3-4 minutos. Houve redução de 5,60% e 14,92% na atividade da malato desidrogenase em R. fruticosus e V. jatamansi, insetos tratados, respectivamente. A atividade da enzima alfa amilase foi reduzida em 6,82% e aumento de 63,63% em R. fruticosus e V. jatamansi, insetos tratados, respectivamente. O presente estudo aborda que ambos os pós de plantas são eficazes contra o gorgulho do celeiro, alterando as atividades enzimáticas, de modo que ambos os pós de plantas possam ser usados ​​como biopesticidas contra pragas de grãos armazenados.

Differential Protein Expressions in Virus-Infected and Uninfected Trichomonas vaginalis

Protozoan viruses may influence the function and pathogenicity of the protozoa. Trichomonas vaginalis is a parasitic protozoan that could contain a double stranded RNA (dsRNA) virus, T. vaginalis virus (TVV). However, there are few reports on the properties of the virus. To further determine variations in protein expression of T. vaginalis, we detected 2 strains of T. vaginalis; the virus-infected (V⁺) and uninfected (V⁻) isolates to examine differentially expressed proteins upon TVV infection. Using a stable isotope N-terminal labeling strategy (iTRAQ) on soluble fractions to analyze proteomes, we identified 293 proteins, of which 50 were altered in V⁺ compared with V⁻ isolates. The results showed that the expression of 29 proteins was increased, and 21 proteins decreased in V⁺ isolates. These differentially expressed proteins can be classified into 4 categories: ribosomal proteins, metabolic enzymes, heat shock proteins, and putative uncharacterized proteins. Quantitative PCR was used to detect 4 metabolic processes proteins: glycogen phosphorylase, malate dehydrogenase, triosephosphate isomerase, and glucose-6-phosphate isomerase, which were differentially expressed in V⁺ and V⁻ isolates. Our findings suggest that mRNA levels of these genes were consistent with protein expression levels. This study was the first which analyzed protein expression variations upon TVV infection. These observations will provide a basis for future studies concerning the possible roles of these proteins in host-parasite interactions.

Effects of dietary leucine supplementation on the hepatic mitochondrial biogenesis and energy metabolism in normal birth weight and intrauterine growth-retarded weanling piglets

BACKGROUND/OBJECTIVES: The study was conducted to evaluate the effects of dietary leucine supplementation on mitochondrial biogenesis and energy metabolism in the liver of normal birth weight (NBW) and intrauterine growth-retarded (IUGR) weanling piglets. MATERIALS/METHODS: A total of sixteen pairs of NBW and IUGR piglets from sixteen sows were selected according to their birth weight. At postnatal day 14, all piglets were weaned and fed either a control diet or a leucine-supplemented diet for 21 d. Thereafter, a 2 × 2 factorial experimental design was used. Each treatment consisted of eight replications with one piglet per replication. RESULTS: Compared with NBW piglets, IUGR piglets had a decreased (P < 0.05) hepatic adenosine triphosphate (ATP) content. Also, IUGR piglets exhibited reductions (P < 0.05) in the activities of hepatic mitochondrial pyruvate dehydrogenase (PDH), citrate synthase (CS), α-ketoglutarate dehydrogenase (α-KGDH), malate dehydrogenase (MDH), and complexes I and V, along with decreases (P < 0.05) in the concentration of mitochondrial DNA (mtDNA) and the protein expression of hepatic peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α). Dietary leucine supplementation increased (P < 0.05) the content of ATP, and the activities of CS, α-KGDH, MDH, and complex V in the liver of piglets. Furthermore, compared to those fed a control diet, piglets given a leucine-supplemented diet exhibited increases (P < 0.05) in the mtDNA content and in the mRNA expressions of sirtuin 1, PGC-1α, nuclear respiratory factor 1, mitochondrial transcription factor A, and ATP synthase, H+ transporting, mitochondrial F1 complex, β polypeptide in liver. CONCLUSIONS: Dietary leucine supplementation may exert beneficial effects on mitochondrial biogenesis and energy metabolism in NBW and IUGR weanling piglets.

In vitro evaluation of the effect of botanical formulations used in the control of Aedes aegypti L. (Diptera: Culicidae) on liver enzymes.

Abstract: INTRODUCTION: Dengue fever is a viral disease transmitted by the Aedes aegypti Linn. (1792) (Diptera: Culicidae) mosquito, which is endemic in several regions of Brazil. Alternative methods for the control of the vector include botanical insecticides, which offer advantages such as lower environmental contamination levels and less likelihood of resistant populations. Thus, in this study, the ability of botanical insecticide formulations to inhibit the activity of the liver enzymes serum cholinesterase and malate dehydrogenase was evaluated. METHODS: Inhibition profiles were assessed using in vitro assays for cholinesterase and malate dehydrogenase activity and quantitated by ultraviolet-visible spectroscopy at 410nm to 340nm. RESULTS Insecticide products formulated from cashew nutshell liquid [A] and ricinoleic acid [B] showed cholinesterase activity levels of 6.26IU/mL and 6.61IU/mL, respectively, while the control level for cholinesterase was 5-12IU/mL. The products did not affect the level of 0.44IU/mL established for malate dehydrogenase, as the levels produced by [A] and [B] were 0.43IU/mL and 0.45IU/mL, respectively. CONCLUSIONS Our findings show that in vitro testing of the formulated products at concentrations lethal to A. aegypti did not affect the activity of cholinesterase and malate dehydrogenase, indicating the safety of these products.

Molecular cloning, purification and immunogenicity of recombinant Brucella abortus 544 malate dehydrogenase protein

The Brucella mdh gene was successfully cloned and expressed in E. coli. The purified recombinant malate dehydrogenase protein (rMDH) was reactive to Brucella-positive bovine serum in the early stage, but not reactive in the middle or late stage, and was reactive to Brucella-positive mouse serum in the late stage, but not in the early or middle stage of infection. In addition, rMDH did not react with Brucella-negative bovine or mouse sera. These results suggest that rMDH has the potential for use as a specific antigen in serological diagnosis for early detection of bovine brucellosis.

Fluvoxamine alters the activity of energy metabolism enzymes in the brain

Objective: Several studies support the hypothesis that metabolism impairment is involved in the pathophysiology of depression and that some antidepressants act by modulating brain energy metabolism. Thus, we evaluated the activity of Krebs cycle enzymes, the mitochondrial respiratory chain, and creatine kinase in the brain of rats subjected to prolonged administration of fluvoxamine. Methods: Wistar rats received daily administration of fluvoxamine in saline (10, 30, and 60 mg/kg) for 14 days. Twelve hours after the last administration, rats were killed by decapitation and the prefrontal cortex, cerebral cortex, hippocampus, striatum, and cerebellum were rapidly isolated. Results: The activities of citrate synthase, malate dehydrogenase, and complexes I, II-III, and IV were decreased after prolonged administration of fluvoxamine in rats. However, the activities of complex II, succinate dehydrogenase, and creatine kinase were increased. Conclusions: Alterations in activity of energy metabolism enzymes were observed in most brain areas analyzed. Thus, we suggest that the decrease in citrate synthase, malate dehydrogenase, and complexes I, II-III, and IV can be related to adverse effects of pharmacotherapy, but long-term molecular adaptations cannot be ruled out. In addition, we demonstrated that these changes varied according to brain structure or biochemical analysis and were not dose-dependent. .

Glutamine and ornithine alpha-ketoglutarate supplementation on malate dehydrogenases expression in hepatectomized rats

PURPOSE: To evaluate the relative gene expression (RGE) of cytosolic (MDH1) and mitochondrial (MDH2) malate dehydrogenases enzymes in partially hepatectomized rats after glutamine (GLN) or ornithine alpha-ketoglutarate (OKG) suplementation. METHODS: One-hundred and eight male Wistar rats were randomly distributed into six groups (n=18): CCaL, GLNL and OKGL and fed calcium caseinate (CCa), GLN and OKG, 0.5g/Kg by gavage, 30 minutes before laparotomy. CCaH, GLNH and OKGH groups were likewise fed 30 minutes before 70% partial hepatectomy. Blood and liver samples were collected three, seven and 14 days after laparotomy/hepatectomy for quantification of MDH1/MDH2 enzymes using the real-time polymerase chain reaction (PCR) methodology. Relative enzymes expression was calculated by the 2-ΔΔC T method using the threshold cycle (CT) value for normalization. RESULTS: MDH1/MDH2 RGE was not different in hepatectomized rats treated with OKG compared to rats treated with CCa. However, MDH1/MDH2 RGE was greater on days 3 (321:1/26.48:1) and 7 (2.12:1/2.48:1) while MDH2 RGE was greater on day 14 (7.79:1) in hepatectomized rats treated with GLN compared to control animals. CONCLUSION: Glutamine has beneficial effects in liver regeneration in rats by promoting an up-regulation of the MDH1 and MDH2 relative gene expression. .

Construction and fermentation control of reductive TCA pathway for malic acid production in Saccharomyces cerevisiae / 生物工程学报

Malic acid is widely used in food, and chemical industries. Through overexpressing pyruvate carboxylase and malate dehydrogenase in pdc1-deficient Saccharomyces cerevisiae, malic acid was successfully produced through the reductive TCA pathway. No malic acid was detected in wild type Saccharomyces cerevisiae, however, 45 mmol/L malic acid was produced in engineered strain, and the concentration of byproduct ethanol also reduced by 18%. The production of malic acid enhanced 6% by increasing the concentration of Ca2+. In addition, the final concentration reached 52.5 mmol/L malic acid by addition of biotin. The increasing is almost 16% higher than that of the original strain.

Repressing malic enzyme 1 redirects glucose metabolism, unbalances the redox state, and attenuates migratory and invasive abilities in nasopharyngeal carcinoma cell lines / 癌症

A large amount of nicotinamide adenine dinucleotide phosphate (NADPH) is required for fatty acid synthesis and maintenance of the redox state in cancer cells. Malic enzyme 1(ME1)-dependent NADPH production is one of the three pathways that contribute to the formation of the cytosolic NADPH pool. ME1 is generally considered to be overexpressed in cancer cells to meet the high demand for increased de novo fatty acid synthesis. In the present study, we found that glucose induced higher ME1 activity and that repressing ME1 had a profound impact on glucose metabolism of nasopharyngeal carcinoma(NPC) cells. High incorporation of glucose and an enhancement of the pentose phosphate pathway were observed in ME1-repressed cells. However, there were no obvious changes in the other two pathways for glucose metabolism: glycolysis and oxidative phosphorylation. Interestingly, NADPH was decreased under low-glucose condition in ME1-repressed cells relative to wild-type cells, whereas no significant difference was observed under high-glucose condition. ME1-repressed cells had significantly decreased tolerance to low-glucose condition. Moreover, NADPH produced by ME1 was not only important for fatty acid synthesis but also essential for maintenance of the intracellular redox state and the protection of cells from oxidative stress. Furthermore, diminished migration and invasion were observed in ME1-repressed cells due to a reduced level of Snail protein. Collectively, these results suggest an essential role for ME1 in the production of cytosolic NADPH and maintenance of migratory and invasive abilities of NPC cells.

Functional difference of malate-aspartate shuttle system in liver between plateau zokor (Myospalax baileyi) and plateau pika (Ochotona curzoniae) / 生理学报

To explore the adaptive mechanisms of plateau zokor (Myospalax baileyi) to the enduring digging activity in the hypoxic environment and of plateau pika (Ochotona curzoniae) to the sprint running activity, the functional differences of malate-aspartate shuttle system (MA) in liver of plateau zokor and plateau pika were studied. The ratio of liver weight to body weight, the parameters of mitochondria in hepatocyte and the contents of lactic acid in serum were measured; the open reading frame of cytoplasmic malate dehydrogenase (MDH1), mitochondrial malate dehydrogenase (MDH2), and the partial sequence of aspartate glutamate carrier (AGC) and oxoglutarate malate carrier (OMC) genes were cloned and sequenced; MDH1, MDH2, AGC and OMC mRNA levels were determined by real-time PCR; the specific activities of MDH1 and MDH2 in liver of plateau zokor and plateau pika were measured using enzymatic methods. The results showed that, (1) the ratio of liver weight to body weight, the number and the specific surface of mitochondria in hepatocyte of plateau zokor were markedly higher than those of plateau pika (P < 0.01 or P < 0.05), but the content of lactic acid in serum of plateau pika was significantly higher than that of plateau zokor (P < 0.01); (2) MDH1 and MDH2 mRNA levels as well as their enzymatic activities in liver of plateau zokor were significantly higher than those of plateau pika (P < 0.01 or 0.05), AGC mRNA level of the zokor was significantly higher than that of the pika (P < 0.01), while no difference was found at OMC mRNA level between them (P > 0.05); (3) mRNA level and enzymatic activity of MDH1 was significantly lower than those of MDH2 in the pika liver (P < 0.01), MDH1 mRNA level of plateau zokor was markedly higher than that of MDH2 (P < 0.01), but the activities had no difference between MDH1 and MDH2 in liver of the zokor (P > 0.05). These results indicate that the plateau zokor obtains ATP in the enduring digging activity by enhancing the function of MA, while plateau pika gets glycogen for their sprint running activity by increasing the process of gluconeogenesis. As a result, plateau pika converts the lactic acid quickly produced in their skeletal muscle by anaerobic glycolysis and reduces dependence on the oxygen.

Change in gastrocnemius dystrophin and metabolic enzymes and increase in high-speed exhaustive time induced by hypoxic training in rats / 生理学报

The aim of the present study was to explore the changes and roles of dystrophin and membrane permeability in hypoxic training. Seventy-two 8-week-old Sprague Dawley (SD) rats were randomly divided into 4 groups, normoxic non-train (NC), normoxic train (NT), hypoxic non-train (HC), and hypoxic train (HT) groups. The rats of each group were randomly divided into three subgroups, non-exhaustive, low-speed exhaustive test and high-speed exhaustive test subgroups. Rats in hypoxia groups lived and were trained in a condition of 12.7% oxygen concentration (equal to the 4 300 m altitude). NT and HT groups received 4 weeks of training exercise. Then the rats in all non-exhaustive subgroups were sacrificed, and gastrocnemii were sampled for the measurements of lactate dehydrogenase (LDH), succinatedehydrogenase (SDH), malate dehydrogenase (MDH) activities. Moreover, serum LDH activity was analyzed. Low-speed exhaustive test and high-speed exhaustive test subgroups received exhaustive tests with 20 (71% VO2max) and 30 m/min speed (86% VO2max), respectively, and their exhaustive times were recorded. The results showed that, compared with normoxic groups, the weights in hypoxia groups exhibited slower increase. The level of dystrophin in HT group without exhaustion test didn't change significantly. The muscle MDH activities were markedly affected by the different oxygen concentration, training and their interaction (P < 0.05), whereas the muscle LDH activities were only affected by the different oxygen concentration (P < 0.05). Serum LDH activities were affected by the interaction of the different oxygen concentration and training (P < 0.05), showing decreased muscle LDH and increased blood LDH activities. The exhaustion time were markedly affected by the different test speed, training and their interaction (P < 0.05), and also affected by the interaction of the different oxygen concentration and training (P < 0.05), but didn't affected by oxygen concentration. The exhaustive time of HT high-speed exhaustive test subgroup was more than NT high-speed exhaustive test subgroup in 30 m/min exhaustion test. Compared with NT high-speed exhaustive test subgroup, HT high-speed exhaustive test subgroup had an earlier fatigue in the test, but had a rapid recovery. These results suggested that hypoxic training can effectively increase the rats' high-speed exhaustive time. The mechanism may be related to an increase in serum LDH caused by the increased membrane permeability after hypoxic training.

Study on the content of myoglobin and the activity of lactate dehydrogenase and malate dehydrogenase in skeletal muscle of tibetan antelope / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To explore the adaptive mechanism to hypoxia in skeletal muscle of tibetan antelope.</p><p><b>METHODS</b>Tibetan sheep which living at the same altitude (4 300 m) with tibetan antelope and low altitude (1 800 m) sheep as control, the content of myoglobin (Mb) and lactic acid (LA), the activity of lactate dehydrogenase (LDH) and malate dehydrogenase (MDH) in skeletal muscles among three animals were analyzed by spectrophotometer.</p><p><b>RESULTS</b>The content of myoglobin in skeletal muscle of tibetan antelope significantly higher than that of tibetan sheep and low altitude sheep (P < 0.05). And the content of LA in skeletal muscle of tibetan antelope significantly lower than that of tibetan sheep and low altitude sheep (P < 0.05), activity of LDH and MDH in skeletal muscle was significantly lower and higher respectively than that of tibetan sheep and low altitude sheep (P < 0.05). There was no significant difference between tibetan sheep and low altitude sheep.</p><p><b>CONCLUSION</b>Tibetan antelope may improve their ability to get oxygen under hypoxia by increasing the content of myoglobin in skeletal muscle, and the proportion of aerobic metabolism is high in skeletal muscle, it may be relate that with high myoglobin content in skeletal muscle, we suppose that high myoglobin content in skeletal muscle of tibetan antelope might be one of the molecular basis to adapt hypoxia.</p>

Antibacterial activity and mechanism of baicalein / 药学学报

Baicalein (BAI) is an effective bactericide. The antibacterial activity and mechanism experiments were carried out by determining conductivity and content of macromolecules of membrane penetrability, the oxidative respiratory metabolism and protein synthesis changes and the inhibition of DNA topoisomerase activities. Electrical conductivity and the number of large molecules of BAI increased 2.48% and 1.8%, respectively, than that of the control. However, the membrane integrity did not destroyed by BAI directly. With BAI treatment, inhibition rates of activities for SDH and MDH were 56.2% and 57.4%, respectively, demonstrating that BAI could inhibit cell respiratory. After treated with BAI for 20 h, the total soluble content of proteins decreased by 42.83%. Moreover, the activities of DNA topoisomerase I and II were inhibited completely by 0.2 mmol x L(-1) BAI. These results indicated that BAI had obvious antibacterial activity on Staphylococcus aureus. The mechanism is that it could affect bacterial membrane penetrability, inhibit protein synthesis and influence SDH, MDH and DNA topoisomerase I and II activities to exert its antibacterial functions.

Effect of glutamine on the mRNA level of key enzymes of malate-aspartate shuttle in the rat intestine subjected to ischemia reperfusion / Efeito da glutamina sobre o nível de RNA Mensageiro das enzimas-chave do ciclo malato-aspartato no intestino de ratos submetidos à isquemia e reperfusão

PURPOSE: To determine the effects of oral L-glutamine (L-Gln) and the dipeptide l-alanyl-glutamine (L-Ala-Gln) upon the activity of the malate-aspartate shuttle in the rat distal small intestine following ischemia and reperfusion. METHODS: Seventy-two Wistar rats (350-400g), were randomized in 2 groups (n = 36): group S (Sham) and Group T (Treatment) and divided into 12 subgroups (n = 6): A-A6, and B1-B6. The subgroups A1-A3 were subjected to sham procedures at 30 and 60 minutes. Thirty minutes before the study, rats were treated with calcium caseinate, 0.5g/Kg (subgroups A1, A4, B1, B4), L-Gln, 0.5g / kg (subgroups A2, A5, B2 and B5) or L-Ala-Gln, 0.75g/Kg (subgroups A3, A6, B3, B6), administered by gavage. Ischemia was achieved by clamping the mesenteric vessels, delimiting a segment of bowel 5 cm long and 5 cm apart from the ileocecal valve. Samples were collected 30 and 60 minutes after start of the study for real-time PCR assay of malate dehydrogenases (MDH1-2) and aspartate-aminotransferases (GOT1-2) enzymes. RESULTS: Tissue MDH and GOT mRNA expression in intestinal samples from rats preconditioned with either L-Gln or L-Ala-Gln showed no significant differences both during ischemia and early reperfusion. CONCLUSION: Activation of the malate-aspartate shuttle system appears not to be the mechanism of glutamine-mediated elevation of glucose oxidation in rat intestine during ischemia/reperfusion injury.

OBJETIVO: Determinar os efeitos da administração oral de L-glutamina (L-Gln) e do dipeptídeo L-alanil-glutamina (L-Ala-Gln) sobre a atividade do ciclo malato-aspartato no intestino delgado distal de ratos após isquemia/reperfusão. MÉTODOS: Setenta e dois ratos Wistar (350-400g) foram randomizados em 2 grupos (n = 36): T grupo S (Sham) e grupo (Tratamento) e distribuídos em 12 subgrupos (n = 6): A-A6, e B1-B6. Os subgrupos A1-A3 foram submetidos a procedimentos "sham" aos 30 e 60 minutos. Trinta minutos antes do estudo, os ratos foram tratados com caseinato de cálcio, 0,5 g/kg (subgrupos A1, A4, B1 e B4), L-Gln, 0,5 g/kg (subgrupos A2, A5, B2 e B5) ou L-Ala -Gln, 0,75g/kg (subgrupos A3, A6, B3, B6), administrado por gavagem. A isquemia foi obtida por pinçamento dos vasos mesentéricos, delimitando um segmento do intestino cinco centímetros de comprimento e 5 cm da válvula ileocecal. Amostras foram coletadas aos 30-60 minutos para ensaio de PCR em tempo real das enzimas malato desidrogenases (MDH1-2), aspartato-aminotransferase (GOT1-2). RESULTADOS: A expressão de MDH e GOT mRNA nas amostras provenientes do intestino delgado de ratos pré-condicionados com L-Gln ou L-Ala-Gln não apresentou diferenças significativas, tanto durante a isquemia como na fase inicial de reperfusão. CONCLUSÃO: Ativação do ciclo malato-aspartato não parece ser o mecanismo de elevação glutamina-mediada da oxidação da glicose no intestino de ratos durante a isquemia / reperfusão.

Effect of overexpression of malate dehydrogenase on succinic acid production in Escherichia coli NZN111 / 生物工程学报

Escherichia coli NZN111 is a double mutant with lactate dehydrogenase (ldhA) and pyruvate formate-lyase (pflB) inactivated. Under anaerobic conditions, disequilibrium of coenzyme NADH and NAD+ causes Escherichia coli NZN111 losing the glucose utilizing capability. In this study, we constructed a recombinant strain E. coli NZN111/pTrc99a-mdh and overexpressed the mdh gene with 0.3 mmol/L of IPTG under anaerobic fermentation condition in sealed bottles. The specific malate dehydrogenase (MDH) activity in the recombinant strain was 14.8-fold higher than that in E. coli NZN111. The NADH/ NAD+ ratio decreased from 0.64 to 0.26 and the concentration of NAD+ and NADH increased 1.5-fold and 0.2-fold respectively. Under anaerobic conditions, the recombinant strain possessed the capability of growth and glucose absorption. We took dual-phase fermentation for succinate production. After the dry cell weight (DCW) reached 6.4 g/L under aerobic conditions, the cell culture was changed to anaerobic conditions. After 15 h, 14.75 g/L glucose was consumed and succinic acid reached 15.18 g/L. The yield of succinic acid was 1.03 g/g Glu and the productivity of succinic acid was 1.012 g/(L x h).

Protective effect of maternal prenatal melatonin administration on rat pups born to mothers submitted to constant light during gestation

We studied the effects of adverse conditions such as constant light (LL) on the circadian rhythm of malate (MDH, EC 1.1.1.37) and lactate (LDH, EC 1.1.1.27) dehydrogenase activities of the testes of male Wistar rats on postnatal day 28 (PN28), anxiety-like behavior (elevated plus-maze test) at PN60 and sexual behavior at PN120. The rats were assigned to mother groups on day 10 of pregnancy: control (12-h light/dark), LL (light from day 10 to 21 of pregnancy), and LL+Mel (LL and sc injection to the mothers of a daily dose of melatonin, 1 mg/kg body weight at circadian time 12, from day 17 to 21 of pregnancy). LL offspring did not show circadian rhythms of MDH (N = 62) and LDH (N = 63) activities (cosinor and ANOVA-LSD Fisher). They presented a 44.7 percent decrease in open-arm entries and a 67.9 percent decrease in time (plus-maze test, N = 15, P < 0.001, Mann-Whitney U-test and Kruskal-Wallis test), an increase in mounting (94.4 percent), intromission (94.5 percent) and ejaculation (56.6 percent) latencies (N = 12, P < 0.01, Mann-Whitney U-test and Kruskal-Wallis test) and lower numbers of these events (61, 59 and 73 percent, respectively; P < 0.01, N = 12) compared to controls. The offspring of the LL+Mel group presented MDH and LDH circadian rhythms (P < 0.05, N = 50, cosinor and ANOVA-LSD Fisher), anxiety-like and sexual behaviors similar to control. These findings supported the importance of the melatonin signal and provide evidence for the protective effects of hormones on maternal programming during gestation. This protective action of melatonin is probably related to its entrainment capacity, favoring internal coupling of the fetal multioscillatory system.

Effect of Weichang'an pill on intestinal digestion enzymes and the AQP4 concentration in proximal colon in IBS-D rats / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the influence of Weichang'an pill on the treatment of diarrhea-predominant irritable bowel syndrome (IBS-D) in model rats.</p><p><b>METHOD</b>Animal model of compound diarrhea was induced by a lactose enriched diet in the Wistar rat, combining with restraint stress. Twenty four female Wistar rats were randomly divided into normal group, model group and 60 mg x kg(-1) x d(-1) Weichang'an pill group. The rate of weight increase, the incubation period of diarrhea and the diarrhea index were observed. Then 45 female Wistar rats randomly divided into five groups: control group, model group and Weichang'an pill groups of high, medium and low doses (80, 60, 40 mg x kg(-1) x d(-1)). The indexes of thymus and spleen were calculated. The activities of LDH, MDH and disaccharidase in intestinal organization were inspected. Serum D-xylose content and the AQP4 concentration in proximal colon were detected.</p><p><b>RESULT</b>After taking Weichang'an pill for 4 days, the rate of weight increase in Weichang'an pill group was higher than the model group's. While the rate of diarrhea was lower significantly. So the best cycle of taking medicine was 4 days. The indexes of thymus and spleen of model group were decreased than that of control group. And the activities of LDH, MDH and disaccharidase in intestinal organization were also decreased. But the AQP4 concentration in proximal colon was increased. Compared with the model group, the indexes of thymus and spleen increased remarkably in the group of medium doses. Meanwhile, the activities of LDH, MDH and disaccharidase increased. But the AQP4 concentration didn't change.</p><p><b>CONCLUSION</b>Weichang'an pill has the effect of antidiarrhea. It can adjust the sugar's catabolism through increasing the activity of intestinal digestive ferment.</p>

Restrição protéica na prenhez: efeitos relacionados ao metabolismo materno / Protein restriction in pregnancy: effects related to dam metabolism

Foram avaliadas as alterações no metabolismo materno durante a prenhez em ratas Wistar, prenhes e não-prenhes, submetidas à restrição protéica, que receberam dietas isocalóricas (15,74 kJ/g), controle ou hipoprotéica (17 por cento versus 6 por cento), distribuídas em quatro grupos (n = 7), quais sejam: controle não-prenhe (CNP) e prenhe (CP) e hipoprotéico não-prenhe (HNP) e prenhe (HP), do 1º ao 18º dia de prenhez. Parâmetros bioquímicos, hormonais e relacionados à síntese de lipídios foram considerados. Utilizou-se ANOVA a duas vias seguido de teste Tukey-HSD e teste t de Student, significância de p < 0,05. A restrição protéica elevou a síntese de lipídios e a atividade da enzima málica (EM) no fígado (FIG) e reduziu a massa ( por cento) e a razão lipí+dio/glicogênio nesse tecido, bem como reduziu a ingestão protéica (total e por cento), o conteúdo ( por cento) de lipídios na glândula mamária (GMA), as proteínas e a albumina séricas, com consequente redução nas massas da placenta e fetos. A prenhez reduziu a proteinemia, a albuminemia, a síntese de lipídios, a atividade da EM, os lipídios e o glicogênio no FIG. Mas elevou a massa corporal final, a massa ( por cento) do tecido adiposo gonadal (GON), do FIG e da GMA, e reduziu a massa ( por cento) da carcaça (CARC), a síntese e o conteúdo de lipídios no GON e, na GMA, o conteúdo de lipídios. A insulinemia elevou-se na prenhez, com glicemia reduzida, caracterizando resistência hormonal. A leptina e a prolactina também se elevaram na prenhez, sendo o aumento maior no HP. A restrição protéica na prenhez modificou o metabolismo materno, alterando a síntese de lipídios no FIG e o perfil hormonal, além de reduzir a massa da placenta e dos fetos.

Metabolism alterations were evaluated in female Wistar rats (dams) during pregnancy. Pregnant and non-pregnant dams submitted to protein restriction, were fed isocaloric (15.74 kJ/g), control or hypoproteic (17 percent vs. 6 percent) diets, and distributed in four Groups (n=7) as follows: non-pregnant control (NPC), pregnant control (PC), non-pregnant hypoproteic (NPH), and pregnant hypoproteic (PH); from Day 1 to Day 18 of pregnancy. Biochemical, hormonal and metabolic parameters related to lipid synthesis were assessed. The two-way ANOVA, followed by Tukey-HSD and Student-t tests were used, with a significance of p< 0.05. Protein restriction elevated lipid synthesis and malic enzyme (ME) activity in the liver, and reduced mass and the lipid/glycogen ratio in this tissue; it also lowered protein ingestion (total and percent), lipid content ( percent) in the mammary gland (MAG), serum proteins and albumin, with consequent reduction of placenta and fetal masses. Pregnancy reduced serum protein and albumin concentrations, lipid synthesis, ME activity, hepatic lipid and glycogen content. However, it increased final body mass; increased relative masses of gonad (GON), liver and MAG; but reduced lipid synthesis and content of GON, lipid content of MAG and the relative mass of carcass. Pregnancy Insulinemia increased during pregnancy with reduced glycemia, characterizing hormonal resistance. Leptin and prolactin were also increased during pregnancy, being the highest increase in observed in HP rats. Protein restriction in pregnancy modified maternal metabolism, altering lipid synthesis in the liver and hormonal profile and decreasing the placenta and fetus masses.

Soluble malate dehydrogenase of Geophagus brasiliensis (Cichlidae, Perciformes): isolated isoforms and kinetics properties

Kinetic properties and thermal stabilities of Geophagus brasiliensis skeletal muscle unfractionated malate dehydrogenase (MDH, EC 1.1.1.37) and its isolated isoforms were analyzed to examine a possible sMDH-B* locus duplication in a fixation process influenced by genetic drift. Two optimal pHs were detected: 7.5 for AB1 unfractionated muscle phenotype and its B1 isoform, and 8.0 for AB1B2 unfractionated muscle phenotype, A and B2 isoforms. While G. brasiliensis A isoform could be characterized as thermostable, the duplicated B isoform cannot be assumed as thermolabile. Km values for isolated B2 isoforms were 1.6 times lower than for B1. A duplication event in progress best explains the electrophoretic six-band pattern detected in G. brasiliensis, which would be caused by genetic drift.

Dehydroepiandrosterone supplement increases malate dehydrogenase activity and decreases NADPH-dependent antioxidant enzyme activity in rat hepatocellular carcinogenesis

Beneficial effects of dehydroepiandrosterone (DHEA) supplement on age-associated chronic diseases such as cancer, cardiovascular disease, insulin resistance and diabetes, have been reported. However, its mechanism of action in hepatocellular carcinoma in vivo has not been investigated in detail. We have previously shown that during hepatocellular carcinogenesis, DHEA treatment decreases formation of preneoplastic glutathione S-transferase placental form-positive foci in the liver and has antioxidant effects. Here we aimed to determine the mechanism of actions of DHEA, in comparison to vitamin E, in a chemically-induced hepatocellular carcinoma model in rats. Sprague-Dawley rats were administered with control diet without a carcinogen, diets with 1.5% vitamin E, 0.5% DHEA and both of the compounds with a carcinogen for 6 weeks. The doses were previously reported to have anti-cancer effects in animals without known toxicities. With DHEA treatment, cytosolic malate dehydrogenase activities were significantly increased by ~5 fold and glucose 6-phosphate dehydrogenase activities were decreased by ~25% compared to carcinogen treated group. Activities of Se-glutathione peroxidase in the cytotol was decreased significantly with DHEA treatment, confirming its antioxidative effect. However, liver microsomal cytochrome P-450 content and NADPH-dependent cytochrome P-450 reductase activities were not altered with DHEA treatment. Vitamin E treatment decreased cytosolic Se-glutathione peroxidase activities in accordance with our previous reports. However, vitamin E did not alter glucose 6-phosphate dehydrogenase or malate dehydrogenase activities. Our results suggest that DHEA may have decreased tumor nodule formation and reduced lipid peroxidation as previously reported, possibly by increasing the production of NADPH, a reducing equivalent for NADPH-dependent antioxidant enzymes. DHEA treatment tended to reduce glucose 6-phosphate dehydrogenase activities, which may have resulted in limited supply for de novo synthesis of DNA via inhibiting the hexose monophophaste pathway. Although both DHEA and vitamin E effectively reduced preneoplastic foci in this model, they seemed to function in different mechanisms. In conclusion, DHEA may be used to reduce hepatocellular carcinoma growth by targeting NADPH synthesis, cell proliferation and anti-oxidant enzyme activities during tumor growth.