Succinate Dehydrogenase Activity Levels Research Articles

Effect of Environmental Temperature on Cypovirus Multiplication and Biomolecules in Silkworm Bombyx mori L.

Two strains of mulberry silkworm, namely Pure Mysore and NB4D2, at fifth instar first day were inoculated with 40l of BmCPV suspension from the stock of 1.215 X 106 PIB/ml in 0.75% of NaCl solution by ‘oral injection’. Three batches of such inoculated worms were allowed to continue larval development at 20±1°C, 24±1°C and 30±1°C in separate BOD incubators. The crude extract of midgut tissue was prepared from the survivals and used to count the total number of polyhedra per larva in each batch. Further, during virus multiplication at different rearing temperatures, the total amount of glucose, proteins and amylase as well as succinate dehydrogenase activity levels in haemolymph were studied. The experimental results clearly indicated that the atmospheric temperature has a direct influence on a number of polyhedral formations and biomolecules.

Effect of Environmental Temperature on Cypovirus Multiplication and Biomolecules in Silkworm Bombyx mori L.

Two strains of mulberry silkworm, namely Pure Mysore and NB4D2, at fifth instar first day were inoculated with 40ml of BmCPV suspension from the stock of 1.215 X 106 PIB/ml in 0.75% of NaCl solution by ‘oral injection’. Three batches of such inoculated worms were allowed to continue larval development at 20±1°C, 24±1°C and 30±1°C in separate BOD incubators. The crude extract of midgut tissue was prepared from the survivals and used to count the total number of polyhedra per larva in each batch. Further, during virus multiplication at different rearing temperatures, the total amount of glucose, proteins and amylase as well as succinate dehydrogenase activity levels in haemolymph were studied. The experimental results clearly indicated that the atmospheric temperature has a direct influence on a number of polyhedral formations and biomolecules.

Embryonic cadmium exposure of male rats alters reproductive functions at adulthood, but without overt alterations in developmental and behavioral outcomes and metabolism

The effects of exposure of pregnant rats to cadmium (Cd) on the developmental and behavioral outcomes, reproductive functions, and metabolism of their male progeny were evaluated. Rats (Wistar) were injected intraperitoneally with either 0.5 or 5.0 µg Cd/kg body weight from day 12 to day 19 of pregnancy. The male offspring were evaluated for their developmental outcomes and behavioral changes. All developmental and behavioral parameters assessed were comparable among the different groups. All male pups were allowed to develop until 100 days of age and evaluated for reproductive end points. The results revealed that although the body weights and relative weights of liver, brain, kidney, testis, and epididymis were not altered, reproductive parameters, including daily sperm production, epididymal sperm numbers, and concentrations of motile, viable, and hypo-osmotic tail-swelled sperm declined significantly in rats exposed to 0.5 and 5.0 µg Cd during embryonic development. In addition, plasma testosterone levels and activity levels of testicular steroidogenic enzymes also decreased in these rats. In the fertility study, although each male in the 0.5, 5.0 µg, and control groups produced a copulatory plug and impregnated a female, the mean number of implantations and live fetuses was reduced significantly in females mated with rats exposed to 0.5 and 5.0 µg Cd during the prenatal period. The general metabolism of the animals exposed to Cd during embryonic development was comparable with the controls as evidenced by no significant changes in the activity levels of succinate dehydrogenase, lactate dehydrogenase, glucose-6-phosphate dehydrogenase, glutamate dehydrogenase, aspartate aminotransaminase, and alanine aminotransaminases in the liver, kidney, and testis. The results thus suggest that maternal Cd exposure during embryonic development markedly affected the spermatogenesis, steroidogenesis, and fertility potential, but without alterations in the development, behavior, and metabolism.

Impact of Acute Lethal and Chronic Sublethal toxicity of Phorate on Succinate Dehydrogenase activity in the Fresh Water Fish Cyprinus carpio

The present study is aimed to investigate the acute and chronic toxicity stress of phorate, induced alterations in the activity levels of Succinate Dehydrogenase (SDH), a vital enzyme of citric acid cycle that catalyses the reversible oxidation of succinate to fumarate. Freshwater fish Cyprinus carpio were exposed to acute lethal toxicity (LC 50 /96 hours - 0.71 ppm/l) of Phorate for one day and 4 days and chronic sublethal toxicity (one-tenth of the LC 50 /96 hours - 0.071 ppm/l) of Phorate for 1, 7, 15 and 30 days. After the completion of stipulated exposure period the SDH enzyme activity levels were estimated in the vital organs of fish such as gill, liver, muscle, kidney and brain. The activity of SDH in all the organs of the fish exposed to phorate decreased at 1 and 4 days of exposure in acute toxicity in the order, day 1>4. The decrease was more at day 4 than at day 1. In the fish exposed to chronic toxicity of phorate, in the activity of SDH from day 1 to day 7 there was increase in the decrement but from day 7 to day 30 it was regressed in all the organs of the fish in the order, day 1>7<15<30. The differences in the SDH activity between controls and experimental were found to be statistically significant (P<0.05). The present study indicates the phorate induced alterations in the activities of carbohydrate metabolic enzyme caused significant metabolic effect on the physiological consequences.

Standardized extract of Withania somnifera (Ashwagandha) markedly offsets rotenone-induced locomotor deficits, oxidative impairments and neurotoxicity in Drosophila melanogaster

Withania somnifera (Ashwagandha, WS) or Indian ginseng possesses multiple pharmacological properties which are mainly attributed to the active constituents, withanolides. Despite its extensive usage as a memory enhancer and a nerve tonic, few attempts have been made to ascertain its usage in the management of Parkinson's disease. In the present study, we investigated the neuroameliorative effects of WS in a rotenone (ROT) model of Drosophila melanogaster (Oregon-K). Initially, we ascertained the ability of WS-enriched diet (0-0.05%) to protect against ROT induced lethality and locomotor phenotype in adult male flies. Further, employing a co-exposure paradigm, we investigated the propensity of WS to offset ROT-induced oxidative stress, mitochondrial dysfunctions and neurotoxicity. WS conferred significant protection against ROT-induced lethality, while the survivor flies exhibited improved locomotor phenotype. Biochemical investigations revealed that ROT-induced oxidative stress was significantly diminished by WS enrichment. WS caused significant elevation in the levels of reduced GSH/non-protein thiols. Furthermore, the altered activity levels of succinate dehydrogenase, MTT, membrane bound enzymes viz., NADH-cytochrome-c reductase and succinate-cytochrome-c reductase were markedly restored to normalcy. Interestingly, ROT-induced perturbations in cholinergic function and depletion in dopamine levels were normalized by WS. Taken together these data suggests that the neuromodulatory effect of WS against ROT- induced neurotoxicity is probably mediated via suppression of oxidative stress and its potential to attenuate mitochondrial dysfunctions. Our further studies aim to understand the underlying neuroprotective mechanisms of WS and withanolides employing neuronal cell models.

Effect of Silver Nanoparticles On Energy Metabolism In Selected Tissues Of Aeromonas Hydrophila Infected Indian Major Carp, Catla Catla

The aim of the present study was to evaluate the effect of silver nanoparticles (AgNPs) on energy metabolic enzymes in selected tissues of Aeromonas hydrophila injected Indian major carp, Catla catla. Fishes exposed to 1/10 th concentration of AgNPs (100 μg/l) did not alter lipid peroxidation levels as compared to 1/5 th concentration of AgNPs in gills, liver and kidney of fishes. Therefore, 1/10 th concentration of AgNPs was selected for subsequent experiments. Significant decrease in the activity levels of succinate dehydrogenase with a significant increase in the activity levels of glucose-6-phosphate dehydrogenase and lactate dehydrogenase in gills, liver and kidney of A. hydrophila infested fishes as compared to controls over a 14-day exposure period. On the other hand, exposure of bacterial infected fishes to 1/10 th concentration of AgNPs reversed the activity levels of enzymes in selected tissues as compared to bacterial infected fishes. However, no significant changes were observed in the activity levels of selected enzymes in tissues of fishes exposed to 1/10 th concentration of AgNPs alone over controls. From the results, it can be concluded that A. hydrophila injection leads to prevalence of anaerobic conditions to meet the demand of energy in tissues whereas AgNPs through their antibacterial properties mitigate A. hydrophila induced changes in oxidative metabolism thereby energy crisis in tissues of fishes. Key WordsA. hydrophila, Catla catla, lipid peroxidation, oxidative enzymes, silver nanoparticles

The Dual-Functioning Fumarate Reductase Is the Sole Succinate:Quinone Reductase in Campylobacter jejuni and Is Required for Full Host Colonization

Campylobacter jejuni encodes all the enzymes necessary for a complete oxidative tricarboxylic acid (TCA) cycle. Because of its inability to utilize glucose, C. jejuni relies exclusively on amino acids as the source of reduced carbon, and they are incorporated into central carbon metabolism. The oxidation of succinate to fumarate is a key step in the oxidative TCA cycle. C. jejuni encodes enzymes annotated as a fumarate reductase (Cj0408 to Cj0410) and a succinate dehydrogenase (Cj0437 to Cj0439). Null alleles in the genes encoding each enzyme were constructed. Both enzymes contributed to the total fumarate reductase activity in vitro. The frdA::cat(+) strain was completely deficient in succinate dehydrogenase activity in vitro and was unable to perform whole-cell succinate-dependent respiration. The sdhA::cat(+) strain exhibited wild-type levels of succinate dehydrogenase activity both in vivo and in vitro. These data indicate that Frd is the only succinate dehydrogenase in C. jejuni and that the protein annotated as a succinate dehydrogenase has been misannotated. The frdA::cat(+) strain was also unable to grow with the characteristic wild-type biphasic growth pattern and exhibited only the first growth phase, which is marked by the consumption of aspartate, serine, and associated organic acids. Substrates consumed in the second growth phase (glutamate, proline, and associated organic acids) were not catabolized by the the frdA::cat(+) strain, indicating that the oxidation of succinate is a crucial step in metabolism of these substrates. Chicken colonization trials confirmed the in vivo importance of succinate oxidation, as the frdA::cat(+) strain colonized chickens at significantly lower levels than the wild type, while the sdhA::cat(+) strain colonized chickens at wild-type levels.

Assessment of respiratory and ion transport potential of Penaeus japonicus gills in response to environmental pollution

The present study aims to pinpoint the respiratory and ion transport potential of gills of Penaeus japonicus living in Abu-Qir Bay, East of Alexandria, Egypt. Our results revealed clear histological impairments in gill structure. These alterations were mainly represented by the presence of large vacuoles in gill axis and gill lamellae. In addition, narrow, disrupted gill lamellae with wavy cuticle and shrunk pillar cells were detected. Moreover, some cells clearly showed pyknosis. Gill ultrastructure also showed abnormal chromatin condensation inside the nucleus. Obvious alterations in the typical shape and structure of mitochondria were observed. Noticeably, the main characteristics of ion regulating gill epithelium were absent thus suggesting a low ion transport activity of P. japonicus gills. Statistically, this was further proved by the significantly higher activity levels of respiratory enzymes, namely, lactate dehydrogenase (LDH) and succinate dehydrogenase (SDH) compared to those of the ion transport enzymes, namely, adenosine triphosphatase (ATPase) and carbonic anhydrase (CA) in gills and haemolymph. SDH activity levels were higher than the corresponding levels of LDH in gills and its own level in haemolymph, indicating a contradictory effect of pollution on respiratory enzyme activity levels.

Old mice present increased levels of succinate dehydrogenase activity and lower vulnerability to dyskinetic effects of 3-nitropropionic acid

Huntington's disease (HD) is a neurodegenerative disorder, with an age-related onset and a progressive development, characterized by choreiform movements. 3-Nitropropionic acid (3NP) induces the inhibition of succinate dehydrogenase (SDH), an increase in oxidative stress and anatomic changes that are related to the pathophysiology of HD. Hence, this toxin is a useful tool to study this pathology. This study compares the effects of 3NP on the development of orofacial dyskinesia (OD) and on SDH activity in young and old mice. Treatment with 3NP (5, 10, 15 or 20 mg/kg once a day, for four days) induced OD in young mice. Old mice presented an increase in the basal level of orofacial movement that was not potentiated by any dose of 3NP. Histochemical analyses showed that old mice presented an increase in the SDH activity. Finally, 3NP induced a decrease in SDH activity at both ages. We suggest that the 3NP-induced OD in young mice is related to the inhibition of SDH activity. In parallel, an enhancement in the basal activity of SDH could be related to the absence of a further increase in the OD presented by old mice treated with 3NP.

Alterations in hepatic metabolism of adult male rats following exposure to hydroxyprogesterone during embryonic development

To investigate the effect of in utero exposure to hydroxyprogesterone (HP) on liver metabolism in adult male albino rats. Pregnant Wistar strain albino rats were exposed to supra-normal levels (10 mg/kg and 25 mg/kg) of HP on days 1, 7 and 14 of pregnancy. The male pups were maintained under controlled conditions and the rats were killed 90 days after birth. The liver tissue was immediately excised, weighed and used for biochemical assays. The activity levels of succinate dehydrogenase (SDH), glutamate dehydrogenase (GDH), glucose-6-phosphate dehydrogenase (G-6-PDH), malate dehydrogenase (MDH) and aminotransaminases were significantly increased in the livers of rats exposed to HP during embryonic development. The lactate dehydrogenase (LDH) activity level was significantly decreased in the liver of experimental rats. Furthermore, there was a significant elevation of activity levels of antioxidant enzymes (glutathione S-transferase [GST] and catalase [CAT]) with an increased lipid peroxidation in the hepatic tissue of experimental rats compared with the control group. The results of the present study suggest that there is an increase in the oxidative metabolism, antioxidative mechanism and levels of lipid peroxidation in rats exposed to HP during embryonic development. The increased aminotransaminase activities in these rats reveal tissue damage and disruption of mitochondrial integrity.

Effect of pyrethroids on carbohydrate metabolic pathways in common carp, Cyprinus carpio.

The activity levels of succinate dehydrogenase (SDH) and glucose-6-phosphate dehydrogenase (G6PD) were assessed in various tissues of Cyprinus carpio var communis which had been exposed to lethal concentrations of group-II pyrethroids (deltamethrin, cypermethrin, fenvalerate and fluvalinate) for a period of 72 h. The results indicated a steady decrease in SDH activity with a concomitant increase in G6PD activity. The decreased SDH activity indicated inhibition of SDH at mitochondrial level and the increased G6PD activity an enhancement of an alternative pathway of carbohydrate metabolism, viz the hexose monophosphate shunt (HMP) or pentose phosphate pathway as a biochemical adaptation to overcome the toxic stress.

Quantitative succinate dehydrogenase histochemistry in the hippocampus of aged rats

Quantitative histochemical methods (microphotometric kinetic and end-point measurements, and morphometric analyses of reactive areas) were used to investigate the levels of succinate dehydrogenase (SDH) in the hippocampus of young adult (3-6 months old) and aged male rats (24-27 months old). Methodological studies concerning the demonstration of SDH activity, which were performed using hippocampi of young animals, revealed a linear relationship between the reaction time and the amount of reaction product for up to 20 min; kinetic (continuous) and end-point measurements provided the same results. In a number of experiments, it was established that an incubation medium consisting of 100 mM succinate, 10 mM sodium azide, 3 mM nitro blue tetrazolium chloride, 0.25 mM phenazine methosulfate, and 7.5% polyvinylalcohol in 0.05 M Hepes buffer (final pH 7.5) was optimal for quantitative SDH histochemistry in the hippocampus. Comparative quantitative investigations of SDH activity in rat hippocampi showed that, in most regions and layers of the hippocampus of both young and aged rats, the levels of SDH activity increased along the rostrocaudal axis of the hippocampus, i.e., higher levels were present in the caudal than in the rostral pole. In both groups, the highest SDH levels were observed in the molecular layer of the cornu ammonis (CA)-1, the CA-3, and the fascia dentata (middle and outer thirds), most of which are termination fields of the excitatory perforant path arising from the regio ento-rhinalis. Furthermore, in almost all of the investigated layers, the older animals exhibited lower SDH levels than young animals. These differences were statistically significant in the molecular layer of the fascia dentata and in most layers of the CA-3. The lower SDH levels in aged animals are discussed in relation to the reduced capacity for energy metabolism in the aging brain.

Effect of cupric chloride on oxidative metabolism in the freshwater teleost, Tilapia mossambica

The freshwater teleost Tilapia mossambica was subjected to lethal ( 6.0 mg · liter −1 = LC 50 48 hr ) and sublethal (1.5 mg · liter −1 copper treatment for 1, 7, and 14 days. The whole animal oxygen consumption and the activity levels of succinate dehydrogenase and lactate dehydrogenase in liver and muscle were studied. The decrease in oxygen consumption and succinate dehydrogenase activity and significant increase in lactate dehydrogenase activity suggest that the stressed fish is meeting its energy requirements through anaerobic oxidation and these enzymes can be used as indicators in monitoring metal-induced toxicity in fish.

The tannery industrial effluent effect on succinate dehydrogenase activity pattern in a freshwater snail,Pila globosa

A high degree of pollution by tannery effluent contamination has been recorded in an irrigation reservoir in North Arcot district, Tamil Nadu. Seepage of contaminants into drinking water wells has also been observed. The tannery effluent is found to inflict changes in succinate dehydrogenase activity levels in the hepatopancreas ofPila globosa, a common inhabitant of the polluted environment.

Succinate dehydrogenase activity in fibres classified by myosin ATPase in three hind limb muscles of rat.

1. Succinate dehydrogenase (SDH) activity was assessed in situ in single fibres of cross-sectioned extensor hallucis longus, extensor digitorum longus, and soleus muscles of rat by means of microphotometric recordings of initial maximum reaction rates. 2. Each fibre assessed for SDH activity was subjectively classified into myosin subgroups by its histochemical reaction for myofibrillar actomyosin ATPase (myosin ATPase) following preincubation at pH 4.6 according to Brooke & Kaiser (1970). 3. The majority of fibres classified into myosin types I and IIa were highly reactive for SDH, such that those myosin groups could be interchangeable with the metabolic subgroups of Peter, Barnard, Edgerton, Gillespie & Stempel (1972); myosin I = slow-twitch oxidative, myosin IIa = fast-twitch oxidative glycolytic. 4. The myosin type IIb fibres, however, demonstrated marked variability in activity levels of SDH. Over 40% of those fibres had high SDH activity, and thus could not be equated with the metabolic subgroup fast-twitch glycolytic. 5. The histochemical reaction for myosin ATPase in muscle fibres therefore cannot be used as a reliable means to predict the fibres' metabolic characteristics.

Mammalian cells with defective mitochondrial functions: a Chinese hamster mutant cell line lacking succinate dehydrogenase activity

A mutant cell line derived from Chinese hamster fibroblasts is described which is defective in oxidative energy metabolism. Glucose is continuously required in the medium. As a result of a block in the Krebs cycle, these cells are auxotrophs for carbon dioxide and asparagine. Several experiments support our conclusion that the mutant cells lack appreciable levels of succinate dehydrogenase activity. Other components of the electron transport chain appear to be fully functional, although there is the possibility that electron transport and oxidative phosphorylation are uncoupled.

Physiological studies on the effects of nutritional imbalance on the central nervous system. II. Effects of thiamine deficiency on oxidative enzymes in the brain of chicken, Gallus domesticus.

The activitiy levels of succinate dehydrogenase, glutamate dehydrogenase and pyruvate dehydrogenase in the fore, mid and hind brain regions of the thiamine deficient chicken, Gallus domesticus were determined. The activity levels of succinate dehydrogenase and glutamate dehydrogenase in all the 3 regions of brain showed augmentation on inducing thiamine deficiency. In contrast the activity levels of pyruvate dehydrogenase decreased in the brain of thiamine deficient animals. It is suggested that these changes in the oxidative enzymes indicate disturbance caused in the operation of the tricarboxylic acid cycle in thiamine deficiency.

Microphotometric determination of enzyme activity in single cells in cryostat sections. I. Application of the gel film technique to microphotometry and studies on the intralobular distribution of succinate dehydrogenase and lactate dehydrogenase activities in rat liver.

A gel film technique was adopted for kinetic enzyme activity determination in single cells using cryostat sections by means of a microscope photometer. The main principle of the method is a comparative activity determination, based on bipositional recording of initial reaction kinetics in two preselected measuring fields in the same tissue section. Systematic model experiments were performed to prove the fulfillment of the following conditions: ( a) validity of Beer's law; ( b) optimal concentrations of substrates, cosubstrates and dye within the reaction film, including evidence that the reaction rate is not limited by insufficient diffusion of these compounds; ( c) proportionality between local enzyme concentration or thickness of tissue sections and the recorded reaction rate; and ( d) specificity of the method as demonstrated by studying reaction rates in the absence of the substrate as well as in the presence of substrate and a specific inhibitor. The validity of the method was also examined by comparing the levels of succinate dehydrogenase activity in various rat tissues, as measured microphotometrically, with the enzyme levels as determined in homogenates. Microphotometric assays for nicotinamide adenine dinucleotide phosphate isocitrate dehydrogenase, lactate dehydrogenase and succinate dehydrogenase are described. Using these techniques it was found that: the periportal and central areas of the hepatic lobule in rat contain the same level of lactate dehydrogenase activity; succinate dehydrogenase activity is 1.6 times higher in the periportal area as compared to the centrilobular area. In experimental thyrotoxicosis, the ratio of enzyme activities in the periportal and central areas was 1.1.