References of "Florkin, Marcel"
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See detailHemolymph: composition
Florkin, Marcel ULg; Jeuniaux, Charles ULg

in Rockstein, Morris (Ed.) The physiology of insecta, Volume V (1974)

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See detailBiochimie et biologie moléculaire
Florkin, Marcel ULg; Schoffeniels, Ernest

Book published by Desoer (1966)

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See detailLes constituants osmotiquement actifs des muscles et leur contribution à la régulation isosmotique intracellulaire chez Limulus polyphemus
Bricteux-Grégoire, S.; Duchâteau-Bosson, Gh.; Jeuniaux, Charles ULg et al

in Comparative Biochemistry and Physiology (1966), 19

1. The chemical composition of the blood and of the intracellular medium of the muscles has been studied in the king crab (Limulus polyphemus) and compared with that of marine decapods (Crustaceans) and ... [more ▼]

1. The chemical composition of the blood and of the intracellular medium of the muscles has been studied in the king crab (Limulus polyphemus) and compared with that of marine decapods (Crustaceans) and of a scorpion, Androctonus australis. 2. The blood of Limulus contains only very small amounts of free amino acids. The amino-acid composition of the muscles of Limulus differs from that of decapods, but is similar to that of the scorpion, with respect to its lower concentration and to the relative proportions of free arginine and free glycine. 3. The intracellular osmolar effectors in Limulus are principally dialysable nitrogenous compounds, other than amino acids and taurine. These unidentified substances play an important role in the isosmotic intracellular regulation which takes place when Limulus is adapted to brackish water (40 % sea water). This is another difference between Limulus and marine decapods ; the latter show a regulation in which free amino acids are among the most important effectors. [less ▲]

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See detailMétabolisme du tréhalose et du glycogène chez le Ver à soie, en relation avec la mue, le filage et les métamorphoses
Florkin, Marcel ULg; Jeuniaux, Charles ULg

in Bulletin de l'Académie royale de Belgique (Classe des Sciences) (1965)

In the silkworm, as is the case in most other insects, trehalose is the principal circulating form of the saccharidic cellular food. The hemolymph contains an enzyme, trehalase, which is normally ... [more ▼]

In the silkworm, as is the case in most other insects, trehalose is the principal circulating form of the saccharidic cellular food. The hemolymph contains an enzyme, trehalase, which is normally inhibited. The inhibation is only suppressed during the periods of molting, causing a decrease of the trahalose concentration and an increase of the amount of free glucose. The muscles and most other tissues, such as the digestive tract, are able to use blood trehalose, thanks to an intracellular trehalase. The epidermis and the silk-glands are devoid of trehalase : they use the free glucose liberated by the hydrolysis of the hemolymph trehalose during the periods of molting and spinning. The problem of the origin of the trehalose is discussed, in the light of recent experiments, in which the incorporation of radioactivity from labelled pyruvate and glucose-1-phosphate into fat-body glycogen and hemolymph trehalose has been followed. The chitin of the cuticle is synthesized at every molting process, partly at the expense of the glucose liberated by the hydrolysis of the trehalose in the hemolymph. On the other hand, the old cuticle is destroyed by the proteolytic and chitinolytic enzymes of the exuvial fluid. The hydrolytic products, especially N-acetylglucosamine, are resorbed by the epidermis and can be used for the biosynthesis of the chitin of the new cuticle. [less ▲]

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See detailContributions à la biochimie du ver à soie. XXX. Biosynthèse de tréhalose et de glycogène à partir de glucose-1-phosphate
Bricteux-Grégoire, S.; Jeuniaux, Charles ULg; Florkin, Marcel ULg

in Comparative Biochemistry and Physiology (1965), 16

1. When injected into silkworms in the middle of the fifth larval instar, labelled G-1-P is principally used for the synthesis of hemolymph trehalose. 2. Glycogen synthesis from the same source in the fat ... [more ▼]

1. When injected into silkworms in the middle of the fifth larval instar, labelled G-1-P is principally used for the synthesis of hemolymph trehalose. 2. Glycogen synthesis from the same source in the fat body proceeds more rapidly in undernourished larvae than in those fed normally. 3. Owing to the poor incorporation of the radioactivity in the glycogen and especially in the trehalose of the fat body, it is suggested that the trehalose could be synthesized from pyruvate elsewhere than in the fat body, and that the biosynthetic pathway of trehalose from pyruvate does not necessarily pass through glycogen. 4. The synthesis of trehalose and glycogen, as well as the hydrolysis of glycogen, could be controlled, directly or indirectly, by the variations of the trehalose level in the hemolymph. 5. The gluconeogenetic pathways in the silkworm are discussed and presented in the form of a partially hypothetical figure. [less ▲]

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See detailConstituants osmotiquement actifs des muscles adducteurs de Gryphaea Angulata adaptée à l'eau de mer ou à l'eau saumâtre
Bricteux-Grégoire, S.; Duchâteau-Bosson, Gh.; Jeuniaux, Charles ULg et al

in Archives Internationales de Physiologie et de Biochimie (1964), 72(5), 835-842

Au cours de l'adaptation de Gryphaea angulata à de l'eau de mer diluée deux fois, les muscles adducteurs se mettent en équilibre avec le milieu intérieur par une diminution de pression osmotique, réalisée ... [more ▼]

Au cours de l'adaptation de Gryphaea angulata à de l'eau de mer diluée deux fois, les muscles adducteurs se mettent en équilibre avec le milieu intérieur par une diminution de pression osmotique, réalisée principalement par la modification de concentration des ions Na, K et Cl, ainsi que de certains acides aminés libres, de la taurine, de la bétaïne et d'autres substances azotées dialysables non identifiées. Ces résultats sont comparés à ceux obtenus précédemment pour Ostrea edulis. [less ▲]

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See detailConstituants osmotiquement actifs des muscles adducteurs d'Ostrea Edulis adaptée à l'eau de mer ou à l'eau saumâtre
Bricteux-Grégoire, S.; Duchâteau-Bosson, Gh.; Jeuniaux, Charles ULg et al

in Archives Internationales de Physiologie et de Biochimie (1964), 72(2), 267-275

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See detailConstituants osmotiquement actifs des muscles adducteurs de Mytilus Edulis adaptée à l'eau de mer ou à l'eau saumâtre
Bricteux-Grégoire, S.; Duchâteau-Bosson, Gh.; Jeuniaux, Charles ULg et al

in Archives Internationales de Physiologie et de Biochimie (1964), 72(1), 116-123

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See detailSur le mécanisme de la régulation de la concentration intracellulaire en acides aminés libres, chez Eriocheir sinensis, au cours de l'adaptation osmotique
Florkin, Marcel ULg; Duchâteau-Bosson, Gh.; Jeuniaux, Charles ULg et al

in Archives Internationales de Physiologie et de Biochimie (1964), 72(5), 892-906

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See detailContributions à la biochimie du ver à soie. XXIX. Composition du cocon, composition de sa séricine et teneur de l'hémolymphe en acides aminés libres, chez une race de Bombyx Mori à cocon de séricine (race Nd)
Bricteux-Grégoire, S.; Duchâteau-Bosson, Gh.; Jeuniaux, Charles ULg et al

in Archives Internationales de Physiologie et de Biochimie (1964), 72(3), 489-495

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See detailContributions à la biochimie du ver à soie. XXVIII. Biosynthèse de tréhalose à partir du pyruvate
Bricteux-Grégoire, S.; Jeuniaux, Charles ULg; Florkin, Marcel ULg

in Archives Internationales de Physiologie et de Biochimie (1964), 72(3), 482-488

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See detailHemolymph : composition. Chapter 2
Florkin, Marcel ULg; Jeuniaux, Charles ULg

in Physiology of insect. Volume 3 (1964)

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See detailFossil proteins of graptolites
Foucart, M.F.; Bricteux-Grégoire, S.; Jeuniaux, Charles ULg et al

in Life Sciences (1964), 4

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See detailCationic pattern of hemolymph in adult hymenoptera
Florkin, Marcel ULg; Jeuniaux, Charles ULg

in Life Sciences (1963), 12

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See detailContributions à la biochimie du ver à soie. XXVII. Tréhalose, tréhalase et mue
Duchâteau-Bosson, Gh.; Jeuniaux, Charles ULg; Florkin, Marcel ULg

in Archives Internationales de Physiologie et de Biochimie (1963), 71(4), 566-576

During the development of the Silkworm, the amount of blood trehalose sharply decreases at each moult, and also during the fasting period corresponding to spinning. The fall of blood trehalose ... [more ▼]

During the development of the Silkworm, the amount of blood trehalose sharply decreases at each moult, and also during the fasting period corresponding to spinning. The fall of blood trehalose concentration during the moults is related to the release of the inhibition of the trehalase present in the hemolymph. The presence of a trehalase in the muscles and in the digestive tract is confirmed. This enzyme has not been detected in the fat body, in the epidermis or in the silkglands. In the fat body, there exists an inverse relationship between glycogen and trehalose, the former disappearing almost completely at each moult, whereas the amount of trehalose tends to remain at a nearly constant level. On the other hand, the bulk of the fat body is consumed to a large extent during the periods of chitin synthesis. The gluconeogenesis during the silkworm development and the metabolism of chitin synthesis at each moult, are discussed in the light of these experimental data. [less ▲]

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See detailConstituants osmotiquement actifs du sang et des muscles du scorpion Androctonus australis L.
Bricteux-Grégoire, S.; Duchâteau-Bosson, Gh.; Jeuniaux, Charles ULg et al

in Archives Internationales de Physiologie et de Biochimie (1963), 71(3), 393-400

The osmotic pressure of the hemolymph of the szcorpion Androctonus australis L., an Arthropod adapted to terrestrial life, is about -1°C. This osmotic pressure results almost entirely from the presence of ... [more ▼]

The osmotic pressure of the hemolymph of the szcorpion Androctonus australis L., an Arthropod adapted to terrestrial life, is about -1°C. This osmotic pressure results almost entirely from the presence of Na+ and Cl-, a situation thus analogous to that found in Crustaceans, but different to that found in Insects, since, in the latter, amino acids are importically active intracellular constituants are mainly low molecular weight nitrogenous molecules, among which amino acids represent 1/5 of the osmolar concentration. As far as blood sugar is concerned, the scorpion's blood, like that of Insects, contains trehalose. [less ▲]

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See detailRôle osmorégulateur intracellulaire du glycocolle et de la taurine chez l'étoile de mer Asterias rubens L.
Jeuniaux, Charles ULg; Bricteux-Grégoire, S.; Florkin, Marcel ULg

in Archives Internationales de Physiologie et de Biochimie (1962), 70(1), 155-156

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See detailRégulation osmotique intracellulaire chez Asterias Rubens L., rôle du glycocolle et de la taurine
Jeuniaux, Charles ULg; Bricteux-Grégoire, S.; Florkin, Marcel ULg

in Cahiers de Biologie Marine (1962)

The mechanism of euryhalinity in Asterias rubens has been studied in a batch collected in the Channel (Coast of Brittany). These starfishes are able to survive for at least a period of 10 days in a medium ... [more ▼]

The mechanism of euryhalinity in Asterias rubens has been studied in a batch collected in the Channel (Coast of Brittany). These starfishes are able to survive for at least a period of 10 days in a medium containing 60% sea water (A:-1°23C), when the transfer from sea water is realized progressively, within three days. During the adaptation to dilluted sea water, the osmotic pressure of the internal medium (perivisceral fluids) is the same as that of the external medium. The tissues of the gastric caeca, however, shows only a small variation of hydration, which implies an effective isosmotic intracellular regulation. The variation in the intracellular concentration of the free glycine and the free taurine in the tissues, plays an important part in this mechanism. [less ▲]

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See detailContribution à la biochimie du ver à soie XXV. Variations de la concentration de la tyrosine de l'hémolymphe au cours du développement de Bombyx Mori L.
Duchâteau-Bosson, Gh.; Jeuniaux, Charles ULg; Florkin, Marcel ULg

in Archives Internationales de Physiologie et de Biochimie (1962), 70(2), 287-291

La teneur en tyrosine de l'hémolymphe s'accroît à la fin de chaque intermue, au cours du développement du ver à soie (4e âge larvaire, 5e âge larvaire, vie nymphale). Elle diminue rapidement aussitôt ... [more ▼]

La teneur en tyrosine de l'hémolymphe s'accroît à la fin de chaque intermue, au cours du développement du ver à soie (4e âge larvaire, 5e âge larvaire, vie nymphale). Elle diminue rapidement aussitôt après l'exuviation, dans les cas de la dernière mue larvaire et de la mue nymphale. La comparaison, au cours du 5e âge, de la tyrosinémie des animaux glandectomisés et de celle des animaux normaux confirme la prise de tyrosine par la glande séricigène. [less ▲]

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See detailConstituants osmotiquement actifs des muscles du crabe chinois Eriocheir Sinensis, adapté à l'eau douce ou à l'eau de mer
Bricteux-Grégoire, S.; Duchâteau-Bosson, Gh.; Jeuniaux, Charles ULg et al

in Archives Internationales de Physiologie et de Biochimie (1962), 70

Les constituants osmotiquement actifs ont été déterminés dans les muscles de crabes chinois (Eriocheir sinensis) adaptés à l'eau douce et à l'eau de mer. La somme des constituants organiques et des ... [more ▼]

Les constituants osmotiquement actifs ont été déterminés dans les muscles de crabes chinois (Eriocheir sinensis) adaptés à l'eau douce et à l'eau de mer. La somme des constituants organiques et des constituants inorganiques dosés rend compte, dans les deux cas, de la totalité ou de la presque totalité de la composante osmotiquement active. Quand les animaux sont transférés de l'eau douce à l'eau de mer, la composante osmotiquement active du muscle s'élève à un niveau qui, en dépit de la forte augmentation de concentration du sang, empêche que le degré d'hydratation des cellules musculaires soit modifié en proportion. La faible modification d'hydratation ne rend nullement compte des variations intracellulaires de la concentration des constituants osmotiquement actifs. Parmi ces derniers, la taurine et la glycocolle-bétaïne ne montrent pas d'augmentation de concentration, tandis que les incréments du sodium, du potassium, du chlorure, de l'alanine, du glycocolle, de l'acide glutamique total, de la proline, de l'arginine (y compris la phosphoarginine), et de l'oxyde de triméthylamine contribuent de manière importante à l'ajustement. La comparaison du "pattern" de la composante osmotiquement active des muscles d'Eriocheir vivant dans l'eau de mer avec celui des muscles de Carcinus maenas, de Nephrops norvegicus et de Homarus vulgaris révèle de grandes similitudes ; par contre, il diffère essentiellement de celui de l'axoplasme des fibres géantes de Loligo pealei. [less ▲]

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