Changes in the level of octopine during the escape responses of the scallop,Pecten maximus (L.)

GÄde, Gerd; Weeda, E.; Gabbott, P.A.

doi:10.1007/bf00689172

Cited by 75 publications

(28 citation statements)

References 12 publications

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“…Argopecten irradians can use about 23-25 % of the glycogen stored in the adductor muscle, Epp et al 1988). Glycolysis leads to octopine formation, largely during recovery after swimming (Grieshaber and Gäde 1977;Gäde et al 1978;Chih and Ellington 1983); succinate formation may result from oxygen deficiency at mitochondrial level. In fact, P e O 2 remains low during recovery, such that scallops initially recover under hypoxic conditions, associated with a rise in P e CO 2 due to insufficient ventilation (MacDonald et al 2006).…”

Section: Mortalitymentioning

confidence: 99%

Impact of ocean acidification on escape performance of the king scallop, Pecten maximus, from Norway

et al. 2012

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The ongoing process of ocean acidification already affects marine life, and according to the concept of oxygen and capacity limitation of thermal tolerance, these effects may be intensified at the borders of the thermal tolerance window. We studied the effects of elevated CO 2 concentrations on clapping performance and energy metabolism of the commercially important scallop Pecten maximus. Individuals were exposed for at least 30 days to 4°C (winter) or to 10°C (spring/summer) at either ambient (0.04 kPa, normocapnia) or predicted future PCO 2 levels (0.11 kPa, hypercapnia). Cold-exposed (4°C) groups revealed thermal stress exacerbated by PCO 2 indicated by a high mortality overall and its increase from 55 % under normocapnia to 90 % under hypercapnia. We therefore excluded the 4°C groups from further experimentation. Scallops at 10°C showed impaired clapping performance following hypercapnic exposure. Force production was significantly reduced although the number of claps was unchanged between normocapnia-and hypercapnia-exposed scallops. The difference between maximal and resting metabolic rate (aerobic scope) of the hypercapnic scallops was significantly reduced compared with normocapnic animals, indicating a reduction in net aerobic scope. Our data confirm that ocean acidification narrows the thermal tolerance range of scallops resulting in elevated vulnerability to temperature extremes and impairs the animal's performance capacity with potentially detrimental consequences for its fitness and survival in the ocean of tomorrow.

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Section: Mortalitymentioning

confidence: 99%

Impact of ocean acidification on escape performance of the king scallop, Pecten maximus, from Norway

et al. 2012

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“…The OcDH-NADH-Larginine complex assembles with a K d of 5.5mmoll -1 during an enthalpically as well as a small entropically favoured reaction (Table1). The concentration of L-arginine, which according to Gäde et al (Gäde et al, 1978) ranges from 24 to 49mmoll -1 in resting and exhausted P. maximus, respectively, is more than sufficient for complex formation even in resting animals. [In order to understand how substrate changes might influence the binding behaviour to enzymes, substrate levels usually given in µmolg -1 wet mass must be converted to concentration in mmoll -1 (Chih and Ellington, 1986).…”

Section: D-octopine Binding and Dead-end Complex Formationmentioning

confidence: 99%

“…The small dissociation constants derived for NADH and D-octopine binding point to a relatively stable ternary complex, which is also likely to exist in vivo (Table1). Comparison of the kinetic data from inhibition studies of OcDH [inhibitor constant K i values range from 1.5 to 4mmoll -1 D-octopine Baldwin and Opie, 1978)] with in vivo substrate concentrations of D-octopine in exhausted or recovering scallops [9-15mmoll -1 (Baldwin and Opie, 1978;Gäde et al, 1978)] also support the proposal that the OcDH-NADH-D-octopine complex is formed in vivo at concentrations of ~12mmoll -1 D-octopine, exerting the known strong product inhibition of OcDH in exhausted scallops (de Zwaan et al, 1980;Chih and Ellington, 1986), D-octopine formation in the forward reaction appears to be substrate inhibited only to a small extent, if at all. Instead, OcDH can function as the terminal step of anaerobic glycolyis until Doctopine reaches concentrations in the range 10-15mmoll -1 during recovery.…”

Section: Substrate and Product Binding To Ocdh Dead-end Complexesmentioning

confidence: 99%

“…Consequently, pyruvate-dependent complex formation will coincide with the onset of strong muscular activity. But in some species, such as P. maximus (Gäde et al, 1978), C. opercularis (Grieshaber, 1978) and P. magellanicus (Livingstone et al, 1981), D-octopine is formed during the first hours of recovery (Fig.3E). Only then will pyruvate levels transiently start to increase, resulting either from an incomplete aerobic pyruvate oxidation or a total lack of oxygen, and the OcDH-NADH-L-arginine-pyruvate complex will associate giving rise to D-octopine accumulation.…”

Section: P Maximusmentioning

confidence: 99%

“…In some species, such as Pecten jacobaeus (Grieshaber and Gäde, 1977), Placopecten magellanicus (de Zwaan et al, 1980;Livingstone et al, 1981) and Argopecten irradians concentricus (Chih and Ellington, 1983;Chih and Ellington, 1986), the D-octopine content increases during escape swimming or during electrical stimulation as, for example, in the adductor muscle of Pecten alba (Baldwin and Opie, 1978) and continues to accumulate to some extent during early recovery. In other bivalves, such as P. maximus or Chlamys opercularis, D-octopine synthesis commences towards the end of swimming, but preferentially accumulates in the muscle during recovery (Gäde et al, 1978;Grieshaber, 1978). Presumably, OcDH activity during swimming and recovery is controlled by a time-dependent increase in the cytoplasmic concentration of substrates as well as by a consecutive or random order of coenzyme and substrate binding to the apoenzyme (Monneuse- Doublet et al, 1978;Schrimsher and Taylor, 1984;Chih and Ellington, 1986).…”

Section: Introductionmentioning

confidence: 99%

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Control of d-octopine formation in scallop adductor muscle as revealed through thermodynamic studies of octopine dehydrogenase

Smits

Schmitt

et al. 2012

Journal of Experimental Biology

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Energy metabolism of arthropods and mollusks during environmental and functional anaerobiosis

GÄde

1983

J. Exp. Zool.

140

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During environmental anaerobiosis, when the whole organism is exposed to anoxic conditions caused by external, physical factors in the microhabitat, arginine phosphate, glycogen, and aspartate (only mollusks) are the substrates for the metabolism. Main end products formed are lactate (Crustacea, Xiphosura, some Gastropoda and Bivalvia), alanine, succinate, and the volatile fatty acids, propionate and acetate (most Gastropoda and most Bivalvia). Because of reduction of the overall metabolism in bivalves, utilization and production rates of substrates and end products, respectively, are low. They are generally faster in Crustacea, which do not reduce their metabolism.During functional anaerobiosis, when the muscle tissue becomes anoxic because of increased work done by the animal, energy is derived from arginine phosphate and glycogen. The main end products formed are lactate (Crustacea), octopine (active Gastropoda and Bivalviaj, and strombineialanopine (some gastropod species). Utilization rates of the phosphagen and production rate of lactate and opines are sometimes more than 500-fold higher than during environmental anaerobiosis. These strong variations in the glycolytic flux are probably regulated by the influence of the phosphagen and adenylates on regulatory enzymes and by the NADHNAD ratio. Key words anaerobiosis in mollusks, anaerobiosis in crustaceans, opine metabolism, succinate pathway, regulation during anaerobiosis Living organisms require continual energy expenditure for the maintenance of function and structure. This energy must be present in the form of ATP' molecules provided by the animal's energy metabolism. Generally, the production of chemical energy from the foodstuff molecules-carbohydrates, fats, and, to some extent, proteins-is achieved by their complete oxidation to COz and H20 with the major amount of ATP produced via oxidative phosphorylation. These processes take place inside the mitochondrion by use of the electron transport chain ending with the reduction of molecular oxygen. Thus, sufficient availability of oxygen is an absolute requisite for the functioning of anaerobic metabolism.Generally, air-breathing animals have no problems in terms of obtaining adequate amounts of oxygen. These organisms typically rely on aerobic energy metzbolism, although under circumstances some tissues (even in mammals) may rely partly or exclusively on anaerobic energy production. These tissues produce lactate anaerobically via glycolysis, which is transported via the blood to aerobic tissues for oxidation (heart) or for resynthesis of glucose (liver). These organisms become only partly anaerobic during exercise when muscle activity needs more energy than is produced aerobically.Animals living in water may continuously face problems of oxygen availability. Compared to air, the amount of oxygen dissolved in water is quite small. Furthermore, the amount of dissolved oxygen can vary dramatically depending on temperature, salinity, and the presence of decaying organic matter. Intertidal species may...

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Changes in the level of octopine during the escape responses of the scallop,Pecten maximus (L.)

Cited by 75 publications

References 12 publications

Impact of ocean acidification on escape performance of the king scallop, Pecten maximus, from Norway

Impact of ocean acidification on escape performance of the king scallop, Pecten maximus, from Norway

Control of d-octopine formation in scallop adductor muscle as revealed through thermodynamic studies of octopine dehydrogenase

Energy metabolism of arthropods and mollusks during environmental and functional anaerobiosis

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