Adenylate Energy Charge Values Research Articles

Adenosine Triphosphate and Adenylate Energy Charge in Ready-to-Eat Food.

It is commonly accepted that dietary nucleotides should be considered as essential nutrients originating mainly but not exclusively from meat and fish dishes. Most research in food science related to nutrition nucleotides is focused on raw products, while the effects of thermal processing of ready-to-eat food on nucleotide content are largely overlooked by the scientific community. The aim of this study is to investigate the impact of thermal processing and cold storage on the content of dietary nucleotides in freshly prepared and canned ready-to-eat meat and fish food. The concentrations of ATP, ADP, AMP, IMP, Ino, and Hx were determined using NMR, HPLC, FPMLC, and ATP bioluminescence analytical techniques; freshness indices K and K1 and adenylate energy charge (AEC) values were estimated to assess the freshness status and confirm a newly unveiled phenomenon of the reappearance of adenylate nucleotides. It was found that in freshly prepared at 65 °C ≤ T ≤ +100 °C and canned food, the concentration of free nucleotides was in the range of 0.001-0.01 µmol/mL and remained unchanged for a long time during cold storage; the correct distribution of mole fractions of adenylates corresponding to 0 < AEC < 0.5 was observed compared to 0.2 < AEC < 1.0 in the original raw samples, with either a high or low content of residual adenylates. It could be assumed that heating at nonenzymatic temperatures T > 65 °C can rupture cell membranes and release residual intracell nucleotides in quite a meaningful concentration. These findings may lead to a conceptual change in the views on food preparation processes, taking into account the phenomenon of the free adenylates renaissance and AEC bioenergetics.

Polyphosphate Plays a Significant Role in the Maturation of Spores in Myxococcus xanthus.

Myxococcus xanthus synthesizes polyphosphates (polyPs) with polyphosphate kinase 1 (Ppk1) and degrades short- and long-chain polyPs with the exopolyphosphatases, Ppx1 and Ppx2, respectively. M. xanthus polyP:AMP phosphotransferase (Pap) generates ADP from AMP and polyPs. Pap expression is induced by an elevation in intracellular polyP concentration. M. xanthus synthesized polyPs during the stationary phase; the ppk1 mutant died earlier than the wild-type strain after the stationary phase. In addition, M. xanthus cells cultured in phosphate-starved medium, H2O2-supplemented medium, or amino acid-deficient medium increased the intracellular polyP levels by six- to ninefold after 6h of incubation. However, the growth of ppk1 and ppx2 mutants in phosphate-starved medium and H2O2-supplemented medium was not significantly different from that of wild-type strain, nor was there a significant difference in fruiting body formation and sporulation in starvation condition. During development, no difference was observed in the adenylate energy charge (AEC) values in the wild-type, ppk1 mutant, and pap mutant strains until the second day of development. However, after day 3, the ppk1 and pap mutants had a lower ADP ratio and a higher AMP ratio compared to wild-type strain, and as a result, the AEC values of these mutants were lower than those of the wild-type strain. Spores of ppk1 and pap mutants in the nutrient medium germinated later than those of the wild-type strain. These results suggested that polyPs produced during development may play an important role in cellular energy homeostasis of the spores by being used to convert AMP to ADP via Pap.

The Effect of Cold-Water Swimming on Energy Metabolism, Dynamics, and Mitochondrial Biogenesis in the Muscles of Aging Rats.

Our study aimed to explore the potential positive effects of cold water exercise on mitochondrial biogenesis and muscle energy metabolism in aging rats. The study involved 32 male and 32 female rats aged 15 months, randomly assigned to control sedentary animals, animals training in cold water at 5 ± 2 °C, or animals training in water at thermal comfort temperature (36 ± 2 °C). The rats underwent swimming training for nine weeks, gradually increasing the duration of the sessions from 2 min to 4 min per day, five days a week. The results demonstrated that swimming in thermally comfortable water improved the energy metabolism of aging rat muscles (increased metabolic rates expressed as increased ATP, ADP concentration, TAN (total adenine nucleotide) and AEC (adenylate energy charge value)) and increased mRNA and protein expression of fusion regulatory proteins. Similarly, cold-water swimming improved muscle energy metabolism in aging rats, as shown by an increase in muscle energy metabolites and enhanced mitochondrial biogenesis and dynamics. It can be concluded that the additive effect of daily activity in cold water influenced both an increase in the rate of energy metabolism in the muscles of the studied animals and an intensification of mitochondrial biogenesis and dynamics (related to fusion and fragmentation processes). Daily activity in warm water also resulted in an increase in the rate of energy metabolism in muscles, but at the same time did not cause significant changes in mitochondrial dynamics.

Energy Status of Stygophilous Amphipod Synurella ambulans as a Promising Biomarker of Environmental Stress in the Hyporheic Zone

The hyporheic zone (HZ) is a sensitive ecotone in river ecosystems because of its biodiversity and susceptibility to human activities. Hyporheic fauna are exposed to multiple stressors that affect the physiology and metabolism of organisms and ultimately ecosystem functioning and biodiversity. This study aimed to quantify adenine nucleotides in the stygophilous freshwater amphipod Synurella ambulans and to evaluate the potential of adenylate energy charge (AEC) as a physiological biomarker of general stress in the HZ of the Sava River at sites with different intensities of environmental and anthropogenic stress. Field studies were conducted seasonally (in December 2018 and April, July, and October 2019) at two sampling sites, one upstream (1-UP) and the other downstream (2-DOWN) of the discharge from the wastewater treatment plant using the standard piston pump. The amphipod population from site 1-UP had significantly higher AEC values than the population from site 2-DOWN in all seasons except summer. Coordinated changes in AEC values with the ATP/ADP ratio indicated differences in energy status between the two populations. However, no changes in the apparent equilibrium constant of adenylate kinase were observed, except in spring at site 1-UP. Multiple linear regression models showed the strongest associations of AEC with Fe and Zn accumulated in amphipods, followed by environmental factors (conductivity, dissolved O2, and concentrations of nitrites and phosphates in the interstitial water). AEC was shown to be a useful index of environmental stress in S. ambulans because it can directly measure the change in available energy and thus the metabolic stress to which the organism is exposed. Finally, seasonal and spatial variations in AEC values reflected ecological status in the HZ.

AMPK regulates behavior and physiological plasticity of Haliotis discus hannai under different spectral compositions

In natural environments, the spectral composition of incident light is often subject to drastic changes due to the abundance of suspended particles, floating animals, and plants in coastal waters. In this study, after four months of culturing under blue light (NB), orange light (NY), dark environment (ND), and natural light (NN), the shell length and weight-specific growth rate in Pacific abalone, Haliotis discus hannai, were ranked in the following order: NY > NN > ND > NB. To understand the growth differences in abalone under these different light environments, we first performed 24-h video monitoring and found that the cumulative movement distance and duration were lowest in group NB, whereas the cumulative movement distance and duration were significantly higher in group ND than in any other group (P < 0.05). In group NB, the time spent hidden underneath the attachment substrate accounted for 81% of the resting time, but this ratio was lowest in group ND, at only 37% (P < 0.05). Next, LC-MS metabolomics identified 201 and 105 metabolites in NB vs. NN, ND vs. NN, and NY vs. NN under the positive and negative ion modes, respectively. According to the fold changes and annotations for differential metabolites in the KEGG enrichment pathways, adenosine, NAD+, cGMP, and arachidonic acid were used as differential metabolism markers, and the AMPK signaling pathway was enriched in every comparison group, and thus investigated further. The gene sequences of three subtypes of AMPK were obtained by cloning and we found that the expression levels of AMPKα and AMPKγ, and the AMP content were significantly higher in group NB than in any other group (P < 0.05). In addition, the ATP contents and adenylate energy charge values were ranked in the following order: NY > NN > ND > NB. According to in situ hybridization analysis, the three subtype genes were widely expressed in the hepatopancreas. Finally, the contents of many lipid metabolites differed significantly among groups and the expression levels of the triglyceride hydrolysis-related gene hormone sensitive lipase and fatty acid oxidation-related gene carnitine palmitoyltransferase 1 were higher in groups ND and NB than in groups NN and NY according to fluorescence quantification PCR (P < 0.05). The expression levels of fatty acid synthase and acetyl-CoA carboxylase were significantly lower in groups ND and NB than in groups NN and NY (P < 0.05). These findings indicated that differences in the spectral composition of incident light could reshape the behavior and physiological metabolism in abalone by influencing the “energy switch” AMPK, thereby providing some insights into the mechanisms that allow nocturnal marine organisms to adapt to different lighting environments.

Impact of transportation and rehydration strategies on the physiological responses of clams (Ruditapes philippinarum)

With the prolongation of the post-catch circulation time, the soft tissue of live clam could gradually decline in its quality. This study investigated the quality changes of clams (Ruditapes philippinarum) during the cold chain transportation, and then focused on the rehydration processes, which included gradient heating rehydration (GR) and sudden heating rehydration (SR). Results showed that a higher survival rate of clams was obtained in the GR stage (95%) clams than that in the SR stage (76%). In addition, both glycogen content and adenylate energy charge (A.E.C) value were also higher in the GR stage (20.49 ± 1.05 mg/g, 70.77 ± 1.76%) than that in the SR stage (15.47 ± 1.83 mg/g, 61.63 ± 1.74%) clams. Conversely, the clams in the GR stage showed lower lactic acid content (0.167 ± 0.003 mmol/g) than that in the SR stage (0.181 ± 0.004 mmol/g). Therefore, during the rehydration processes, the GR was a better approach to preserve the quality of clams when compared with the SR. This work could provide reference to preserve the quality of clams and reduce the economic loss of clams during the transportation and rehydration process.

Temperature effects on the nutritional quality in Pacific oysters (Crassostrea gigas) during ultraviolet depuration

Oysters are mainly consumed in the raw form, so it is important to get rid of bacteria and other harmful substances. Ultraviolet (UV) sterilization depuration is a commonly used method and does not produce chemical residues or act directly on shellfish, resulting in minimal adverse effects on flavor. This study simulated the industrial depuration process using UV sterilization to depurate Pacific oysters (Crassostrea gigas). The effects of different temperatures (15, 20, and 25 °C) on the quality and taste components of C. gigas were investigated by measuring changes in physiological and biochemical indexes in C. gigas tissue samples. At the end of depuration, no oyster mortality occurred, but it was up to 55% at 25 °C at 84 h. Glycogen content decreased the most at 25 °C at 48 h. The fatty acid content was higher at 20 and 25 °C. Succinic acid content decreased significantly and was higher at 20 and 25 °C at 48 h with no significant difference. Total free amino acid (FAA) content was significantly higher at 20 °C, however, there were no significant differences in nucleotide content at any temperature at 48 h. Adenylate energy charge (AEC) values decreased, with higher values at 15 and 25 °C, and equivalent umami concentration (EUC) values increased, with higher values at 20 and 25 °C. Considering the changes in flavor substances and mortality rate, 20°C is the appropriate temperature for UV sterilization depuration of C. gigas to produce better edible quality. © 2021 Society of Chemical Industry.

Changes in the Concentration of Purine and Pyridine as a Response to Single Whole-Body Cryostimulation.

To our knowledge, this is the first study in which we provide evidence that a single whole-body cryostimulation treatment leads to changes associated with erythrocyte energy metabolism. These changes are beneficial from the point of view of cellular bioenergetics, because they are associated with an increase in ATP concentration and erythrocyte energy potential expressed by an increase in the ATP/ADP and ATP/AMP ratios and the value of adenylate energy charge (AEC). In addition, as affected by cryogenic temperatures, there is a decrease in the concentration of purine catabolism products, i.e., inosine and hypoxanthine in the blood.

Lactate dehydrogenase in fish spermatozoa and its role in sperm cell bioenergetics

Lactate dehydrogenase (LDH) in spermatozoa of three fish species was studied to determine its role in sperm cell bioenergetics in normal and polluted conditions. The adenylate energy charge (AEC) has been used as the measure of energy storage for adenine nucleotide pool of living cells and tributyltin (TBT) as a model toxicant. It was demonstrated that carp Cyprinus carpio Linnaeus, 1758 spermatozoa exhibit higher LDH activity than catfish Clarias gariepinus (Burchell, 1822) and herring Clupea harengus Linnaeus, 1758 spermatozoa. Native electrophoretic pattern of LDH from spermatozoa compared to somatic tissues extract shows nine LDH isoenzymes in carp spermatozoa, two LDH isoenzymes in herring and one LDH isoenzyme in catfish spermatozoa. It was confirmed that lactate plus pyruvate, which are the substrates for LDH seems to maintain AEC value. It indicates ATP synthesis in tricarboxylic acid cycle prevails upon the ATP utilization in catfish spermatozoa. It was noticed that LDH-B4 is more strongly inhibited by TBT in herring than the nine LDH isoenzymes in carp spermatozoa which confirms that herring spermatozoa may be more sensitive for pollution by decreasing their energetic state. LDH role in maintaining physiological bioenergetic state of spermatozoa is also discussed.

The Effect of Training on Erythrocyte Energy Status and Plasma Purine Metabolites in Athletes.

This study aimed to assess the changes in red blood cell (RBC) energy status and plasma purine metabolites concentration over a one-year training cycle in endurance-trained (EN; n = 11, 20–26 years), and sprint-trained (SP; n = 11, 20–30 years) competitive athletes in comparison to recreationally-trained individuals (RE; n = 11, 20–26 years). Somatic, physiological, and biochemical variables were measured in four training phases differing in exercise load profile: transition, general, specific, and competition. Significantly highest values of RBC adenylate energy charge (AEC; p ≤ 0.001), ATP-to-ADP and ADP-to-AMP ratios (p ≤ 0.05), and plasma levels of adenosine (Ado; p ≤ 0.05) were noted in the competition phase in the EN and SP, but not in the RE group. Significantly lowest plasma levels of adenosine diphosphate (ADP; p ≤ 0.05), adenosine monophosphate (AMP; p ≤ 0.001), inosine (Ino; p ≤ 0.001), and hypoxanthine (Hx; p ≤ 0.001) accompanied by higher erythrocyte hypoxanthine-guanine phosphoribosyltransferase (HGPRT) activity (p ≤ 0.001), were observed in the competition phase in both athletic groups. No significant alterations were found in the erythrocyte concentration of guanine nucleotides in any group. In conclusion, periodized training of competitive athletes’ results in a favorable adaptation of RBC metabolism. The observed changes cover improved RBC energy status (increased AEC and ATP/ADP ratio) and reduced purine loss with more efficient erythrocyte purine pool recovery (increased HGPRT activity and plasma levels of Ado; decreased Hx and Ino concentration).

Expeditious prediction of post-mortem changes in frozen fish meat using three-dimensional fluorescence fingerprints.

The present study was conducted to characterize fluorophores in the fish body using three-dimensional fluorescence fingerprints (3D-FFs) and to utilize these 3D-FFs obtained from frozen horse mackerel (Trachurus japonicus) fillets to predict early post-mortem changes. Alive fish were sacrificed instantly, preserved in ice until 2 days, and then filleted, vacuum packed, and frozen. Subsequently, 3D-FFs of the frozen fillets were acquired using F-7000 aided with a fiber probe. Post-mortem freshness changes were tracked by measuring adenylate energy charge (AEC) values and nicotinamide adenine dinucleotide (NAD and NADH) content. Partial least squares regression models for predicting AEC values and NADH content in frozen fish meat showed good fittings, with R2 of 0.90 and 0.85, by utilizing eight and five excitation wavelengths, respectively, based on their fluorescence features acquired from standard fluorophores. This novel approach of 3D-FFs could be utilized as an efficient technique for at-line monitoring of frozen fish quality.

Effects of stunning/slaughtering methods in rainbow trout (Oncorhynchus mykiss) from death until rigor mortis resolution

The effects of stunning/slaughtering methods (carbon monoxide asphyxia, CO; electroshock, E; asphyxia in the air, A) were studied in rainbow trout kept in freshwater at 12°C. The fish were analysed for blood parameters, rigor mortis evolution, fillets shape changes over 48h, and ATP depletion and Adenylate Energy Charge (AEC) in muscle immediately after death. Treatment A was most stressful giving the lowest pH values during rigor evolution, the highest concentration of lactate (6.31mM) in plasma and the lowest AEC values in the muscle.None of the three-stunning/slaughtering methods affected perimeter, length and height of the fillets, with exception for the area at 24h and 48h post mortem, which was significantly reduced by CO treatment (CO<A<E). Globally, CO and E treatments showed the highest ability in preserving muscle energy immediately after death, whereas treatment E resulted the most suitable method for slaughtering, based on blood and muscle indicators. Statements of relevance1.The application of CO as slaughtering/killing method on rainbow trout, focusing on the effects produced in the pattern of some analytical parameters during the first period post mortem2.The use of carbon monoxide for killing fish has been only recently experimented and only in Atlantic salmon.3.Improve the knowledge about the use of CO, due the scarcity of information in scientific literature

Energy Charge, Redox State, and Metabolite Turnover in Single Human Hepatocytes Revealed by Capillary Microsampling Mass Spectrometry

Metabolic analysis of single cells to uncover cellular heterogeneity and metabolic noise is limited by the available tools. In this study, we demonstrate the utility of capillary microsampling electrospray ionization mass spectrometry with ion mobility separation for nontargeted analysis of single cells. On the basis of accurate mass measurements and collision cross-section determination, a large number of chemical species, 22 metabolites and 54 lipids, were identified. To assess the cellular response to metabolic modulators, the adenylate energy charge (AEC) levels for control and rotenone treated cells were evaluated. A significant reduction in the AEC values was observed for rotenone treated cells. For the cells under oxidative stress, the mean value for the [reduced glutathione (GSH)]/[oxidized glutathione (GSSG)] ratio was significantly decreased, whereas the distribution of the [uridine diphosphate N-acetylhexosamine (UDP-HexNAc)]/[uridine diphosphate hexose (UDP-hexose)] ratio exhibited dramatic tailing to higher values. Lipid turnover rates were studied by pulse-chase experiments at the single cell level.

Energy response of swimming crab Portunus trituberculatus to thermal variation: Implication for crab transport method

Temperature variation and air exposure are two predominant abiotic stressors during the transport and storage of Portunus trituberculatus . To understand the effects of these factors on P. trituberculatus , we examined the hemolymph (hemocyanin, glucose and lactate level) and muscle indicators (glycogen content, metabolic enzymes activity and energy status) through laboratory experiments. Energy status was evaluated by measuring changes in total adenine nucleotide (TAN) concentration, ATP, ADP, AMP, ADP/ATP, AMPATP, adenylate energy charge value (AEC) and the apparent equilibrium constant for adenylate kinase ( K ′ ADEN ). It was found that thermal variation significantly influenced ( P < 0.05) the energy metabolism of crabs by increasing lactate level, ADP and AMP content, cytochrome c oxidase (CCO) and lactate dehydrogenase (LDH) activity and the ratio of ADP/ATP and AMP/ATP and by decreasing glucose and ATP content, AEC and K ′ ADEN value at high temperature. At lower temperature, all parameters except the hemocyanin and lactate level were similar between immersed and aerial exposed crabs ( P > 0.05), indicating that the maintenance of energy homeostasis was independent of environment media. However, at higher temperature, air exposure resulted in more perturbation of energy metabolism in the crabs compared to immersion, as a greater decrease in hemocyanin, ATP, AEC and K ′ ADEN level ( P < 0.05), and a greater increase in glucose, ADP, AMP, ADP/ATP and AMP/ATP level ( P < 0.05) were observed in aerial exposed crabs. In summary, high temperature especially during air exposure could lead to a severe stress in P. trituberculatus , and the perturbation of energy status as a result of mismatch between energy demand and supply is a possible inducer of crab death. • Energy produce capability is reduced in P. trituberculatus subject to thermal variation or aerial exposure. • Aerial exposure leads to more energy demand and consequently a more severe disturbance of energy status. • The transport of P. trituberculatus without water seems to be a better alternative at lower temperature.

Subcellular energy balance of Odontesthes bonariensis exposed to a glyphosate-based herbicide

Water pollution by agrochemicals is currently one of the most critical problems for the conservation of aquatic ecosystems. Glyphosate [N-(phosphonomethyl) glycine); PMG] is the main broad-spectrum post emergence herbicide used for the control of a wide range of pests in soybean crops. Adenylate energy charge (AEC) reflects the energy balance of the cells, a measure of the energy available from the adenylate pool: adenosine triphosphate (ATP), adenosine diphosphate (ADP) and adenosine monophosphate (AMP). Background adenylates, phosphagens and the AEC index of two year old Odontesthes bonariensis were determined in some tissues by HPLC, and the impact on subcellular energy balance of sublethal glyphosate-based herbicide exposure was analyzed. The doses used were 0 (control tank), 1 or 10mg PMGL−1, trials were carried out during 15 days. AEC values in brain, liver and muscle from control fish were 0.37±0.02, 0.49±0.05 and 0.56±0.03, respectively (means±SEM). While brain ATP concentrations were undetectable (hence low values of AEC), the muscle tissue showed the highest concentrations of the more energetic molecules: 0.18μmole ATPg−1 and 8μmole phosphocreatineg−1 (PCrg−1). In the brain, no significant changes were detected in exposed fish compared to controls. Instead, in both the liver and muscle of animals exposed to the highest concentration of the herbicide, significant changes in the AEC (reduction of 26% and 15%, p<0.05) with respect to the control group were determined. Chronic exposure (15 days) of Odontesthes bonariensis to 1 and 10mgL−1 of formulated glyphosate did not affect brain AEC. However, the highest concentration of the herbicide produced a significant decrease in liver and muscle AEC manifesting adverse sublethal effects on the energy metabolism. These results suggest the usefulness of AEC as a biomarker of fish glyphosate exposure.

On the dynamics of the adenylate energy system: homeorhesis vs homeostasis.

Biochemical energy is the fundamental element that maintains both the adequate turnover of the biomolecular structures and the functional metabolic viability of unicellular organisms. The levels of ATP, ADP and AMP reflect roughly the energetic status of the cell, and a precise ratio relating them was proposed by Atkinson as the adenylate energy charge (AEC). Under growth-phase conditions, cells maintain the AEC within narrow physiological values, despite extremely large fluctuations in the adenine nucleotides concentration. Intensive experimental studies have shown that these AEC values are preserved in a wide variety of organisms, both eukaryotes and prokaryotes. Here, to understand some of the functional elements involved in the cellular energy status, we present a computational model conformed by some key essential parts of the adenylate energy system. Specifically, we have considered (I) the main synthesis process of ATP from ADP, (II) the main catalyzed phosphotransfer reaction for interconversion of ATP, ADP and AMP, (III) the enzymatic hydrolysis of ATP yielding ADP, and (IV) the enzymatic hydrolysis of ATP providing AMP. This leads to a dynamic metabolic model (with the form of a delayed differential system) in which the enzymatic rate equations and all the physiological kinetic parameters have been explicitly considered and experimentally tested in vitro. Our central hypothesis is that cells are characterized by changing energy dynamics (homeorhesis). The results show that the AEC presents stable transitions between steady states and periodic oscillations and, in agreement with experimental data these oscillations range within the narrow AEC window. Furthermore, the model shows sustained oscillations in the Gibbs free energy and in the total nucleotide pool. The present study provides a step forward towards the understanding of the fundamental principles and quantitative laws governing the adenylate energy system, which is a fundamental element for unveiling the dynamics of cellular life.

Influence of sampling, storage, processing and optimal experimental conditions on adenylate energy charge in penaeid shrimp

Adenylate energy charge (AEC) has been used as a practical index of the physiological status and health in several disciplines, such as ecotoxicology and aquaculture. This study standardizes several procedures for AEC determination in penaeid shrimp that are very sensitive to sampling. We concluded that shrimp can be frozen in liquid nitrogen and then stored at -76?C for up to two years for further analysis, or freshly dissected and immediately homogenized in acid. Other cooling procedures, such as immersion in cold water or placing shrimp on ice for 15 min resulted in 50% and 73% decreases in ATP levels, and 9-fold and 10-fold increases in IMP levels, respectively. Optimal values of AEC (0.9) were obtained in shrimp recently transferred from ponds to indoor conditions, but decreased to 0.77 after one month in indoor tanks when stocked at high densities; the AEC re-established to 0.85 when the shrimps were transferred to optimal conditions (lower density and dark tanks). While the levels of arginine phosphate followed the same pattern, its levels did not fully re-establish. Comparison of different devices for sample homogenization indicated that a cryogenic ball mill mixer is the more suitable procedure.

Formation of adenylate energy charge (AEC) versus the fluorine content in forest soil in the area affected by emission from Police Chemical Plant

Activity of most enzymes of the key-metabolic pathways depend on the content of adenine nucleotides, such as ATP, ADP and AMP, in cells. Based on the level of these nucleotides, the adenylate energy charge (AEC) was defined as AEC = ([ATP] + 0.5[ADP]) : ([ATP] + [ADP] + [AMP]). Theoretically, AEC values can range from 0 to 1 and represent the physiological state of a soil microbial population. Soil microorganisms and the enzymes they secrete are connected with biological processes which form soil fertility in all ecosystems, including forests. Forests are such ecological systems which are an integral complex and their dysfunction could be caused by permanent influence of anthropogenic factors, including industrial emission of gases and dusts. The aim of this study was the determination of changes in adenylate energy charge values and fluorine content in the humus layer of forest-podsol soils affected by the emission of Police Chemical Plant. During a year, soil samples were taken five times (in October 2007, February, April, June and September 2008) from five different sites Wkrzanska Forest near Wegornik, Tatynia, Tanowo, Trzeszczyn and Mœciecino. In the samples, concentration of fluorine, both water-soluble (extracted by 0.01 M CaCl 2 ) and potentially accessible to plants (extracted by 2 M HClO 4 ), was assayed by potentiometry. Additionally, the content of adenine nucleotides was assayed by chromatography. Based on the content of nucleotides, adenylate energy charge values in soil were calculated. The AEC values and fluorine content in soil depended on a distance from the emitter and the dates on which the samples were taken. In order to determine the relationships between the fluorine content and AEC values, Pearson’s correlations coefficients were calculated. Between

The parameters of energetic status of the wild Atlantic salmon (Salmo salar L.) spermatozoa

The energetic status of fresh sperm of wild Atlantic salmon (Salmo salar L.) was presented in selected males (n=10) with motility rate ≥80%. Purine and pyridine nucleotides: adenosine triphosphate (ATP), adenosine diphosphate (ADP), adenosine monophosphate (AMP), guanosine triphosphate, guanosine diphosphate, guanosine monophosphate, inosine monophosphate, nicotinamide adenine dinucleotide and nicotinamide adenine dinucleotide phosphate; nucleosides: adenosine, guanosine and inosine; bases: hypoxanthine, xanthine and uric acid were determined using the high-performance liquid chromatography method. The average value of adenylate energy charge in the group was 0.77 ± 0.10, and the mean total adenine nucleotide content (TAN) was 65.1 ± 18.3 pmol × 10−6 spermatozoa. The mean concentrations of ATP, ADP and AMP were 43.5, 11.8 and 9.9 pmol × 10−6 spermatozoa respectively. The concentrations of the other energetic nucleotides studied were lower. In all males studied (n=23) with a motility rate from 0% to 95%, no statistically significant correlation between the per cent of motile sperm and ATP concentration was found (Rs=0.35), whereas the correlation between the per cent of motile sperm and ADP was statistically significant (Rs=0.60). A negative correlation was found between hypoxanthine and the per cent of motile spermatozoa (Rs=−0.44). Our results suggest that hypoxanthine is the final product of salmon spermatozoa of adenine nucleotide catabolism.

Altered energy status of primary cerebellar granule neuronal cultures from rats exposed to lead in the pre- and neonatal period

This paper examines the effect of pre- and neonatal exposure of rats to lead (0.1% lead acetate in drinking water, resulting in rat offspring whole blood lead concentration (Pb-B) 4 μg/dL) on the energy status of neuronal mitochondria by measuring changes in ATP, ADP, AMP, adenosine, TAN concentration, adenylate energy charge value (AEC) and mitochondrial membrane potential in primary cerebellar granule neurons (CGC) in dissociated cultures. Fluorescence studies were performed to imaging and evaluate mitochondria mass, mitochondrial membrane potential, intracellular and mitochondrial reactive oxygen species (ROS) production. The Na +/K + ATPase activity in intact CGC was measured spectrophotometrically. Our data shows that pre- and neonatal exposure of rats to Pb, even below the threshold of whole blood Pb value considered safe for people, affects the energy status of cultured primary cerebellar granule neurons through a decrease in ATP and TAN concentrations and AEC value, inhibition of Na +/K + ATPase, and increase in intracellular and mitochondrial ROS concentration. These observations suggest that even these low levels of Pb are likely to induce important alterations in neuronal function that could play a role in neurodegeneration.