Development of glutamotransferase and glutamine synthetase in the nervous system of the chick

Rudnick, Dorothea; Waelsch, Heinrich

doi:10.1002/jez.1401290206

Cited by 75 publications

(12 citation statements)

References 12 publications

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“…T h e assumption for the existence of a tectal as well as a retinal response to spectral stimulation is made, because on day 17 of incubation the retinal rods and cones are completely differentiated in chick embryos (Rudnick 8c Waelsch, 1955) and retinal pigments are present (Wald & Zussman, 1938). I t is very important that the spectral responses are recorded uniformly from the same group of tectal neurons (without a shift in the electrode).…”

Section: Discussionmentioning

confidence: 99%

Functional development of optic afferent system in chick embryos

Sedláček

1969

Developmental Psychobiology

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A description is given of evoked activity in the optic lobes of chick embryos to different types of peripheral stimulation. During prehatching development (day 18–21 of incubation) the functional lability of optic neurons increases, as tested with repetitive stimulation (1–10 cps) and with paired flash stimuli. Maturation of the “OFF”‐evoked response proceeds in the same developmental period. This development is characterized by a decrease in the duration of light exposure necessary to produce the “OFF”‐response, by an increase in the amplitude of this type of evoked response, and by a decrease in latency, which becomes shorter than the latency of the “ON”‐response. The development of color differentiation (in the range of 486–687 mμ) has been studied according to the parameters of tectal evoked response (latency, amplitude, duration, steepness of crescent and decrescent part of negative spike). On day 19, there is evidence for differentiation of only 27 signs of the evoked response, particularly for blue and red color. The number of differential signs increases up to 40, until hatching (i.e.,) for blue, red, and orange colors.

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Section: Discussionmentioning

confidence: 99%

Functional development of optic afferent system in chick embryos

Sedláček

1969

Developmental Psychobiology

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“…(7,19,20), and chick embryos (14). A glutamine synthetase which synthesizes glutamine from glutamic acid and ammonia, or glutamyl hydroxamic acid from glutamic acid and hydroxylamine, with adenosine triphosphate (ATP) as energy donor, has also been reported from various sources, including higher plants (5 synthetase preparations from pea seeds have been shown to have transferase activity even after purification of 1000-to 4000-fold (6,18).…”

Section: Livingston G E Anid Markakis P Biosynthesismentioning

confidence: 99%

“…These compounds all are derivatives of 2,3-dimethoxy-5-methyl benzoquinone with a long side chain composed of monounsaturated isoprenoid units substituted in the 6 position (14). The convention has been introduced of using a subscript after coenzyme Q to indicate the number of isoprenoid units in the side chain.…”

mentioning

confidence: 99%

Amide Metabolism in Higher Plants. III. Distribution of Glutamyl Tranferase and Glutamine Synthetase Activity.

Loomis

1959

Plant Physiol.

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“…0.1 M-tris-potassium chloride buffer (pH 7.3) at 00 C using a Waring blender. The mixture was centrifuged at 4,000 revs/min for 5 min and the supernatant fluid was used as a source of glutamine synthetase activity, which was estimated by the method of Rudnick, Mele & Waelsch (1955). A typical incubation mixture contained the following: sodium L-glutamate (100 pmoles), adenosine triphosphate (10 jmoles), magnesium chloride (40 pmoles), 2-amino-2-(hydroxymethyl)propane-1,3-diol hydrochloride (tris) (100 jmoles), potassium cyanide (80 pmoles), hydroxylamine (40 Mmoles) and the enzyme solution (0.3 ml.)…”

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

The Metabolism of Thalidomide: Some Biological Effects of Thalidomide and Its Metabolites

Fabro

Schumacher

Smith

et al. 1965

British Journal of Pharmacology and Chemotherapy

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In the preceding paper (Schumacher, Smith & Williams, 1965) it was shown that thalidomide was converted in the body into a number of compounds, several of which are derivatives of the amino acids, glutamic acid and glutamine. Since thalidomide is racemic, some of its breakdown products will, therefore, contain amino acid residues of the unnatural D-series. Any of the biological effects (embryotoxic, neurotoxic and sedative) of thalidomide could be due to the drug or its metabolites interfering with the normal metabolism of L-glutamine and L-glutamic acid. These amino acids are prominently involved in the metabolic activity of the central and peripheral nervous system (Tower, 1960), although their role in foetal development is not clear. There are indications, however, that they may be involved in morphogenesis (Deuchar, 1962).In this paper the effects of thalidomide and its hydrolysis products on three enzymes concerned with glutamate metabolism (namely glutamine synthetase, glutamate decarboxylase and glutamate dehydrogenase), on the embryos of pregnant rabbits and on the hexobarbitone-induced sleeping time in rats, will be described. METHODSGlutamine synthetase. An acetone-dried powder of rat brain was prepared. Brains from freshly killed adult female rats were rapidly removed, cooled on ice, weighed and homogenized in ten volumes of ice-cold acetone. The resulting suspension was centrifuged at 4,000 revs/min for 10 min and the acetone was poured off. The solid residue was resuspended in a further ten volumes of ice-cold acetone and centrifuged as before. The acetone layer was again decanted and the solid residue was dried at 40 C in vacuo over silica gel and paraffin wax. To prepare an extract containing glutamine synthetase activity, the acetone-dried powder (0.5 g) was homogenized for 2 min in 10 ml. 0.1 M-tris-potassium chloride buffer (pH 7.3) at 00 C using a Waring blender. The mixture was centrifuged at 4,000 revs/min for 5 min and the supernatant fluid was used as a source of glutamine synthetase activity, which was estimated by the method of Rudnick, Mele & Waelsch (1955). A typical incubation mixture contained the following: sodium L-glutamate (100 pmoles), adenosine triphosphate (10 jmoles), magnesium chloride (40 pmoles), 2-amino-2-(hydroxymethyl)propane-1,3-diol hydrochloride (tris) (100 jmoles), potassium cyanide (80 pmoles), hydroxylamine (40 Mmoles) and the enzyme solution (0.3 ml.) in a final volume of 2 ml. Substances to be tested for inhibitory activity were dissolved in the tris buffer. The low solubility of thalidomide precluded it from being tested at the same concentration as those used for other compounds. Hydroxylamine was freshly prepared before use by neutralizing hydroxylamine hydrochloride with 2 N-sodium hydroxide. The preparations were incubated at 370 C for 20 min and then the reaction was stopped by adding 1.5 ml. of a solution containing equal volumes of 5% (w/v) ferric chloride (in 0.1 N-hydrochloric acid), 2.5 N-hydrochloric acid and 15% (w/v) trichloracetic acid. The react...

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Development of glutamotransferase and glutamine synthetase in the nervous system of the chick

Cited by 75 publications

References 12 publications

Functional development of optic afferent system in chick embryos

Functional development of optic afferent system in chick embryos

Amide Metabolism in Higher Plants. III. Distribution of Glutamyl Tranferase and Glutamine Synthetase Activity.

The Metabolism of Thalidomide: Some Biological Effects of Thalidomide and Its Metabolites

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