Anaerobiosis, recovery from anoxia, and the role of strombine and alanopine in the oyster Crassostrea virginica

1983 ◽  
Vol 61 (12) ◽  
pp. 2682-2687 ◽  
Author(s):  
John C. Eberlee ◽  
Janet M. Storey ◽  
Kenneth B. Storey

Tissue-specific metabolism was monitored in gill, mantle, and adductor muscle of the oyster Crassostrea virginica over a time course of 96 h of anoxia followed by 48 h of recovery from anoxia. Succinate and alanine accumulated as products of anaerobic metabolism while aspartic acid was utilized as a substrate of anaerobiosis. The imino acids alanopine and strombine were not produced during anoxia. During aerobic recovery tissue levels of metabolites returned to control levels, succinate within 2 h in mantle and gill and 6 h in muscle, while restoration of alanine levels required about 24 h. Aspartate pools were restored in 4 to 6 h. Alanopine and strombine accumulated during the recovery period. By 2 h of recovery, alanopine content of mantle and gill had risen by 1.3 and 0.5 μmol/g, respectively, while in adductor muscle both alanopine and strombine accumulated with net increases of 2 and 2.7 μmol/g. Imino acid content declined after 6–12 h of recovery returning to control levels by 24 h. The roles of alanopine and strombine in the oyster are not as products of anaerobic metabolism but rather as products of glycolytic function during recovery. The increased metabolic rate associated with the return to aquatic conditions appears to require some glycolytic energy production to meet overall tissue energy requirements of recovery.

1996 ◽  
Vol 199 (4) ◽  
pp. 911-921 ◽  
Author(s):  
E Finke ◽  
H O Pörtner ◽  
P G Lee ◽  
D M Webber

Squid (Lolliguncula brevis) were exercised in a tunnel respirometer during a stepwise increase in water velocity in order to evaluate the anaerobic threshold, i.e. the critical swimming speed above which anaerobic metabolism contributes to energy production. The average anaerobic threshold was found at speeds of 1.5-2 mantle lengths s-1. Above this velocity, alpha-glycerophosphate, succinate and octopine started to accumulate in the mantle tissue. ATP levels fell and phospho-L-arginine was progressively depleted, while the levels of glucose 6-phosphate and inorganic phosphate rose. The finding of a simultaneous onset of anaerobic metabolism in the cytosol and the mitochondria indicates that a limited oxygen supply to the mitochondria elicits anaerobic energy production. This finding is opposite to the situation found in many other vertebrate and invertebrate species, in which energy requirements in excess of aerobic energy production are covered by anaerobic metabolism, with mitochondria remaining aerobic. In L. brevis, swimming at higher speeds is associated with a small factorial increase in metabolic rate based on a high resting rate of oxygen consumption. Pressure recordings in the mantle cavity support this finding, indicating a high basal level of spontaneous activity at rest and a small rise in mean pressure at higher swimming velocity. Bursts of higher pressures from the jet support elevated swimming speeds and may explain the early transition to anaerobic energy production which occurs when pressure amplitudes exceed 1.2-1.5 kPa or when mean pressure rises above 0.22-0.25 kPa. The finding of mitochondrial hypoxia at a low critical speed in these squid is interpreted to be related to their life in shallow coastal and bay waters, which limits the necessity to maintain high swimming velocities. At increased swimming velocities, the animals oscillate between periods of high and low muscular activity. This behaviour is interpreted to reduce transport cost and to permit a longer-term net use of anaerobic resources when speed exceeds the critical value or when the squid dive into hypoxic waters. The simultaneous onset of anaerobic metabolism in the cytosol and the mitochondria emphasizes that squid generally make maximal use of available oxygen under resting conditions, when their energy requirements are the highest among marine invertebrates.


2021 ◽  
Vol 12 ◽  
Author(s):  
Cesar Augustus Zocoler de Sousa ◽  
Ana Paula Renno Sierra ◽  
Bryan Steve Martínez Galán ◽  
Jaqueline Fernanda de Sousa Maciel ◽  
Richelieau Manoel ◽  
...  

Endurance exercise induces an increase in the expression of exercise-induced peptides that participate in the repair and regeneration of skeletal muscles. The present study aimed to evaluate the time course and role of exercise-induced cytokines in muscle damage and repair after a marathon race. Fifty-seven Brazilian male amateur marathon finishers, aged 30–55 years, participated in this study. The blood samples were collected 24 h before, immediately after, and 24 and 72 h after the São Paulo International Marathon. The leukogram and muscle damage markers were analyzed using routine automated methodology in the clinical laboratory. The plasma levels of the exercise-induced cytokines were determined using the Human Magnetic Bead Panel or enzyme-linked immunosorbent assays [decorin and growth differentiation factor 15 (GDF-15)]. A muscle damage was characterized by an increase in plasma myocellular proteins and immune changes (leukocytosis and neutrophilia). Running the marathon increased interleukin (IL)-6 (4-fold), IL-8 (1.5-fold), monocyte chemoattractant protein-1 (2.4-fold), tumor necrosis factor alpha (TNF-α) (1.5-fold), IL-10 (11-fold), decorin (1.9-fold), GDF-15 (1.8-fold), brain-derived neurotrophic factor (BDNF) (2.7-fold), follistatin (2-fold), and fibroblast growth factor (FGF-21) (3.4-fold) plasma levels. We also observed a reduction in musclin, myostatin, IL-15, and apelin levels immediately after the race (by 22–36%), 24 h (by 26–52%), and 72 h after the race (by 25–53%). The changes in BDNF levels were negatively correlated with the variations in troponin levels (r = −0.36). The variations in IL-6 concentrations were correlated with the changes in follistatin (r = 0.33) and FGF-21 (r = 0.31) levels after the race and with myostatin and irisin levels 72 h after the race. The changes in IL-8 and IL-10 levels had positive correlation with variation in musclin (p < 0.05). Regeneration of exercise-induced muscle damage involves the participation of classical inflammatory mediators, as well as GDF-15, BDNF, follistatin, decorin, and FGF-21, whose functions include myogenesis, mytophagia, satellite cell activation, and downregulation of protein degradation. The skeletal muscle damage markers were not associated to myokines response. However, BDNF had a negative correlation with a myocardial damage marker. The classical anti-inflammatory mediators (IL-10, IL-8, and IL-6) induced by exercise are associated to myokines response immediately after the race and in the recovery period and may affect the dynamics of muscle tissue repair.


Author(s):  
W.A. Jacob ◽  
R. Hertsens ◽  
A. Van Bogaert ◽  
M. De Smet

In the past most studies of the control of energy metabolism focus on the role of the phosphorylation potential ATP/ADP.Pi on the regulation of respiration. Studies using NMR techniques have demonstrated that the concentrations of these compounds for oxidation phosphorylation do not change appreciably throughout the cardiac cycle and during increases in cardiac work. Hence regulation of energy production by calcium ions, present in the mitochondrial matrix, has been the object of a number of recent studies.Three exclusively intramitochondnal dehydrogenases are key enzymes for the regulation of oxidative metabolism. They are activated by calcium ions in the low micromolar range. Since, however, earlier estimates of the intramitochondnal calcium, based on equilibrium thermodynamic considerations, were in the millimolar range, a physiological correlation was not evident. The introduction of calcium-sensitive probes fura-2 and indo-1 made monitoring of free calcium during changing energy metabolism possible. These studies were performed on isolated mitochondria and extrapolation to the in vivo situation is more or less speculative.


1979 ◽  
Vol 42 (04) ◽  
pp. 1193-1206 ◽  
Author(s):  
Barbara Nunn

SummaryThe hypothesis that platelet ADP is responsible for collagen-induced aggregation has been re-examined. It was found that the concentration of ADP obtaining in human PRP at the onset of aggregation was not sufficient to account for that aggregation. Furthermore, the time-course of collagen-induced release in human PRP was the same as that in sheep PRP where ADP does not cause release. These findings are not consistent with claims that ADP alone perpetuates a collagen-initiated release-aggregation-release sequence. The effects of high doses of collagen, which released 4-5 μM ADP, were not inhibited by 500 pM adenosine, a concentration that greatly reduced the effect of 300 μM ADP. Collagen caused aggregation in ADP-refractory PRP and in platelet suspensions unresponsive to 1 mM ADP. Thus human platelets can aggregate in response to collagen under circumstances in which they cannot respond to ADP. Apyrase inhibited aggregation and ATP release in platelet suspensions but not in human PRP. Evidence is presented that the means currently used to examine the role of ADP in aggregation require investigation.


2021 ◽  
Vol 22 (15) ◽  
pp. 8197
Author(s):  
Kinga Kęska ◽  
Michał Wojciech Szcześniak ◽  
Adela Adamus ◽  
Małgorzata Czernicka

Low oxygen level is a phenomenon often occurring during the cucumber cultivation period. Genes involved in adaptations to stress can be regulated by non-coding RNA. The aim was the identification of long non-coding RNAs (lncRNAs) involved in the response to long-term waterlogging stress in two cucumber haploid lines, i.e., DH2 (waterlogging tolerant—WL-T) and DH4 (waterlogging sensitive—WL-S). Plants, at the juvenile stage, were waterlogged for 7 days (non-primed, 1xH), and after a 14-day recovery period, plants were stressed again for another 7 days (primed, 2xH). Roots were collected for high-throughput RNA sequencing. Implementation of the bioinformatic pipeline made it possible to determine specific lncRNAs for non-primed and primed plants of both accessions, highlighting differential responses to hypoxia stress. In total, 3738 lncRNA molecules were identified. The highest number (1476) of unique lncRNAs was determined for non-primed WL-S plants. Seventy-one lncRNAs were depicted as potentially being involved in acquiring tolerance to hypoxia in cucumber. Understanding the mechanism of gene regulation under long-term waterlogging by lncRNAs and their interactions with miRNAs provides sufficient information in terms of adaptation to the oxygen deprivation in cucumber. To the best of our knowledge, this is the first report concerning the role of lncRNAs in the regulation of long-term waterlogging tolerance by priming application in cucumber.


2016 ◽  
Vol 7 (2) ◽  
pp. 1-14
Author(s):  
Rachida Khaled ◽  
Lamine Hammas

The diffusion of the technological innovation can affect the agricultural sector in the three-sided (social, economic and environmental), a hand, it can contribute to solve problems of the agricultural sector: the effects of the climatic changes, the farming exodus and the migration and the problems of poverty and it can improve the agricultural productivity. But on the other hand, he can lead to new problems, such as depletion of energy resources caused by excessive use of energizing technologies, pollution of air and water and the destruction of soil by industrial waste. This paper aims to theoretically and empirically analyze the role of technological innovation in improving agricultural sustainability through the impact of mechanization on agricultural productivity, energy production and net income per capita for a panel of three Maghreb countries (Algeria, Morocco and Tunisia) during the period 1997-2012. By using simultaneous equations, the authors' finding that technological innovation cannot achieve the purpose of sustainable development in the agriculture sector in the Maghreb countries through the negative impact of mechanization and research and development on agricultural productivity.


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