Adenylate energy charge, arginine phosphate and ATPase activity in juvenile Homarus americanus during the molt cycle

Dehn, Paula F.; Haya, K.; Aiken, D. E.

doi:10.1016/0305-0491(85)90377-3

Cited by 17 publications

(13 citation statements)

References 25 publications

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“…The ATP levels are in the same range as reported for other crustaceans (Dehn et al, 1985;Onnen and Zebe, 1983;Dickson and Giesy, 1982;Harms et al, 1990). However, studies on the influence of nutrition on ATP levels gave contradictory results, e.g.…”

Section: Food Supply and Temperaturesupporting

confidence: 73%

Tissue-specific distribution of pyruvate kinase isoforms improve the physiological plasticity of Northern krill, Meganyctiphanes norvegica

Salomon

Saborowski

2006

Journal of Experimental Marine Biology and Ecology

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The Northern krill, Meganyctiphanes norvegica (Crustacea, Euphausiacea) is widely distributed in the northern and northeastern parts of the Atlantic Ocean where it faces rapid variations in water temperatures and food. We studied the physiological potential of krill to compensate for environmentally induced metabolic changes. Two isoforms of the glycolytic key enzyme pyruvate kinase (PKI and PKII, EC 2.7.1.40) were partly purified from M. norvegica by anion exchange chromatography. Specific activities and catalytic properties of each isoform were determined in whole body extracts as well as in selected organs and tissues of males and females. Both PK-isoenzymes differed slightly in their temperature profiles, their activation energy and their molecular weights. PKI showed a high affinity for the substrate PEP and was not affected by fructose-1.6-bisphosphate (FBP). In contrast, PKII showed low affinity for PEP but was strongly activated by FBP, up to 40-fold. The specific PK-activity of whole organisms was lower in females (44.9 F 4.8 Ud g ww À 1 ) than in males (61.3 F 7.7 Ud g ww À 1). In females PK II represented 20% of the total PK-activity while it was only 10% in males. Highest PK activities were present in the hearts, the eyes, pleopods and in the thoracopods. In the stomachs and the midgut glands PK activities were low. Almost all organs contained PKI and PKII. However, PKI prevailed in the abdomens, the pleopods, the thoracopods, and in the thoracic muscles. PKII dominated in the eyes, the midgut glands and in the ovaries. Experiments showed that the tissue concentrations of FBP increased with food uptake and temperature. The expression of two PK-isoforms with different kinetic properties and the mediation of substrate affinity by FPB is a powerful tool to immediately regulate glycolytic energy flows in different organs. The krill is capable of adjusting energy consumption to changes in nutritional conditions as well as variations of environmental temperatures. D

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Section: Food Supply and Temperaturesupporting

confidence: 73%

Tissue-specific distribution of pyruvate kinase isoforms improve the physiological plasticity of Northern krill, Meganyctiphanes norvegica

Salomon

Saborowski

2006

Journal of Experimental Marine Biology and Ecology

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“…Diagram illustrating N:P ratio range (by atoms) obtained in this study (interstage variability), in freshwater sites (interspecific variability), and in marine systems (intersystem variability). In fact, pronounced changes in this pool do occur during the molt cycle in Homarus americanus (Dehn et al 1985). Mean N:P ratios for the different sites are indicated as x.…”

Section: Sources Of Interstage Variabilitymentioning

confidence: 99%

“…Although some authors estimated that the adenine nucleotide pool contribution to whole-organism phosphorus is not large (see Elser et al 1996;data from DeZwann and Thillart 1985), absolute levels of this pool within animals have been shown to vary (Giesy and Dickson 1981) and decrease with age. In fact, pronounced changes in this pool do occur during the molt cycle in Homarus americanus (Dehn et al 1985). Because metamorphosis is a more energy-demanding process per unit time for structural changes than molting, absolute requirements of P linked to adenine nucleotides should be highest before metamorphosis.…”

Section: Sources Of Interstage Variabilitymentioning

confidence: 99%

Linking Life History Strategies and Ontogeny in Crustacean Zooplankton: Implications for Homeostasis

Villar‐Argaiz

Medina‐Sánchez

Carrillo

2002

Ecology

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Work to date has established that consumers are constrained in their chemical content variability. Such a constraint generates many different kinds of ecological relationships ranging from aspects of animal mineral nutrition to factors affecting consumerdriven nutrient recycling. Although previous studies have shown variation in zooplankton nutrient content within and between taxa, most stoichiometric studies assume that consumers are homeostatic in their elemental composition. In this paper, this assumption is reexamined as we describe the variability in the elemental content of the calanoid copepod Mixodiaptomus laciniatus Lilljeborg throughout its ontogeny (interstage variability) and for its specific developmental stages (intrastage variability). Mean copepod carbon content as dry mass increased significantly during ontogeny from 36.3% in nauplii to 51.5% in immature copepodites and 55.8% in adults. Mean phosphorus content decreased from 0.98% in nauplii to 0.87% in immature copepodites and 0.51% in adults. The copepod molar C:N:P ratio was 99:3:1 for nauplii, 165:13:1 for immature copepodites, and 234:25:1 for adults. These ontogenetic variations in stoichiometry within a single copepod species are comparable to the previously described range between taxa. Stoichiometric and physiological approaches are used as complementary tools to explain the two-part life history strategy of this copepod. First, the nauplii and early copepodite stages (CI-CIV) with high carbon demands adopt a growth strategy during which carbon sources are mainly allocated to increases in body size. The susceptibility of these copepodite stages to carbon limitation is reflected in the decline in the carbon content for a given stage (e.g., from 66% to 38% C in CII) and in the 40-fold decrease in neutral-to-polar lipid ratio toward the end of the ice-free season, suggesting a mobilization of food reserves toward growth. In contrast, copepodite stage CV and adults with less carbon demands for growth followed a survival-reproductive strategy, where the invariability in carbon content as dry mass (near 60%) and in neutralto-polar lipid ratio through time indicates no accumulation of storage lipids, but instead an allocation of resources toward maintenance or reproduction. The basic assumption of predictions of stoichiometric models that elemental composition remains constant with time are not supported by changes in the intrastage carbon and nitrogen contents of Mixodiaptomus laciniatus. Thus, we suggest that the idea of strict homeostasis may be replaced with the concept of rheostasis, which allows the homeostatic regulatory mechanisms of an organism to adjust to a changing environment over time.

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“…The total protein content was determined according to the method of Braford [21]. The total ATPase activity was analyzed according to a procedure described by Dehn et al [22]. Antioxidant responses including the activities of superoxide dismutase (SOD), peroxidase (POD) and glutathione S-transferase (GST) and the content of MDA were determined according to previous studies [18,23].…”

Section: Analysis Of Atpase Activity and Antioxidant Responsesmentioning

confidence: 99%

Interactions between Microcystis aeruginosa and coexisting amoxicillin contaminant at different phosphorus levels

Liu

Chen

Xiao

et al. 2015

Journal of Hazardous Materials

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Adenylate energy charge, arginine phosphate and ATPase activity in juvenile Homarus americanus during the molt cycle

Cited by 17 publications

References 25 publications

Tissue-specific distribution of pyruvate kinase isoforms improve the physiological plasticity of Northern krill, Meganyctiphanes norvegica

Tissue-specific distribution of pyruvate kinase isoforms improve the physiological plasticity of Northern krill, Meganyctiphanes norvegica

Linking Life History Strategies and Ontogeny in Crustacean Zooplankton: Implications for Homeostasis

Interactions between Microcystis aeruginosa and coexisting amoxicillin contaminant at different phosphorus levels

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