Eine Schnellmethode zur Bestimmung von Tritium, Radiokohlenstoff und Radioschwefel in beliebigem organischem Probenmaterial mittels des Flüssigkeits‐Scintillations‐Zählers

Kalberer, Fabian; Rutschmann, J.

doi:10.1002/hlca.19610440718

Cited by 296 publications

(34 citation statements)

References 11 publications

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“…Glucose in the hydrolysate was estimated and [14C] carbon counted after the addition of 10 ml toluene scintillator : Triton-X-100 (2:1). Alternatively, carrier glucose was added and after evaporating to dryness in a rotary film evaporator, glucosazones were prepared and burnt by the Sch6niger oxygen flask technique of Kalberer and Rutschmann [1961].…”

Section: Analytical Techniquesmentioning

confidence: 99%

The Importance of Glucose in the Oxidative Metabolism of the Pregnant Uterus and Its Contents in Conscious Sheep With Some Preliminary Observations on the Oxidation of Fructose and Glucose by Fetal Sheep

Setchell¹,

Bassett²,

Hinks³

et al. 1972

Exp Physiol

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The day after implantation of catheters under general anaesthesia, u-[14C] glucose was infused intravenously into four conscious ewes about 130 days pregnant, and into two fetuses about 130 days old. u-[14C] fructose was infused into three other similar fetuses.It could be calculated that the pregnant uterus with its contents derived about 40% of its CO2 from blood glucose and oxidized directly about 45% of the glucose utilized. The total uptake of glucose by the uterus and contents accounted for about 70% of the glucose metabolism of the pregnant ewes, but the proportion of C02 derived by the pregnant ewes from glucose was no higher than for non-pregnant ewes or rams. The total oxygen consumption of uterus and contents was comparable to the extra oxygen used by a ewe when pregnant, as measured by calorimetry. The specific radioactivity of fetal blood fructose was still only about 60% of that of maternal blood glucose after 5 hours infusion which suggests that there are other precursors for fetal fructose besides maternal glucose.[14C] from fructose and glucose infused into the fetus was converted into C02 and glycogen and [14C] from fructose was converted to glucose by the fetus or placenta. The degree of incorporation of both sugars into C02 and glycogen was similar but neither sugar could account for more than a fraction of the CO2 production.It has been stated [Kronfeld, 1958;Reid, 1968] that the pregnant uterus is a major user of glucose in the body and that most of its oxidative metabolism depends on blood glucose. In the present experiments an attempt has been made to put these deductions on a quantitative basis in conscious animals.In addition, some preliminary experiments are reported in which we measured the rate of fetal utilization of fructose in conscious animals. The high concentration of fructose in the blood of fetal lambs was demonstrated many years ago [Bacon and Bell, 1946;Cole and Hitchcock, 1946] and fetal fructose is formed in the placenta from glucose [Huggett, Warren and Warren, 1951;Alexander, Huggett and Widdas, 1951;Alexander, Andrews, Huggett, Nixon and Widdas, 1955;Britton, Huggett and Nixon, 1967]. All the evidence to date suggests that this sugar is not metabolized to any great extent by the lamb [Huggett, 1961;Alexander, Britton and Nixon, 1966;Alexander, Britton, Cohen and Nixon, 1969]. Alexander, Britton and Nixon [1970] have shown that in the isolated perfused fetus only about 3% of the CO2 production came from fructose, and they suggested that glucose was probably the major fetal metabolite. However, we have shown that [14C] from

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Section: Analytical Techniquesmentioning

confidence: 99%

The Importance of Glucose in the Oxidative Metabolism of the Pregnant Uterus and Its Contents in Conscious Sheep With Some Preliminary Observations on the Oxidation of Fructose and Glucose by Fetal Sheep

Setchell¹,

Bassett²,

Hinks³

et al. 1972

Exp Physiol

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“…A Packard Model 3310 liquid scintillation counter was used for measurement of "C. Lipid extractions were done in duplicate and from each extract three fatty acid analyses were made. The total "C in grains and lipid extracts was determined by Schoeniger digestion (17).…”

mentioning

confidence: 99%

Influence of Temperature and Seed Ripening on the in-vivo Incorporation of ¹⁴CO₂ into the Lipids of Oat Grains (Avena sativa L.)

Beringer

1971

Plant Physiol.

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To elucidate the influence of growth temperature and of stage of maturity on lipid synthesis in seeds, oat plants (Avena sativa nuda L., variety NOS) were fed with "CO2 at different stages after flowering, and the "C-incorporation into the grain lipids was determined at 2, 24, and 48 hours after the end of "CO2-application. By changing growth temperature from 12 C to 28 C after the application of "CO2 to intact plants, a higher "C-labeling of saturated fatty acids was found at the higher temperature. At 28 C, palmitic and stearic acids contained 23% and 9% respectively of total fatty acid-"C shortly after the "CO2-application, whereas at 12 C the corresponding values were 19% and 4%, respectively. Within 2 days "C-activity of saturated fatty acids decreased at both temperatures, but to a lesser degree at 28 C. The higher "C-labeling of saturated fatty acids and its lower decrease within 2 days at 28 C clearly show a direct influence of temperature on fatty acid biosynthesis in oat grains.At all stages of grain growth, oleic acid had the highest "Cactivity of all fatty acids shortly after the "CO2-application. However, "C activity of oleic acid rapidly decreases in favor of linoleic acid. With increasing maturity, the intensity of lipid synthesis in the grains decreases; simultaneously, the relative amount of "C-saturated fatty acids increases primarily at the expense of "C-oleic acid. These tendencies, which were observed in oat plants grown at To clarify the nature of these temperature effects, the incorporation of "CO2 into the grain lipids was studied at different stages of grain maturation-grain growth at day temperatures of 12 C and 28 C respectively-to determine whether different growth temperatures influence grain lipids by acceleration or retardation of maturity. As a second objective, a "CO2 feeding experiment with intact plants was undertaken to indicate whether there is a direct effect of growth temperature on fatty acid synthesis in grains.MATERIALS AND METHODS Oat plants (Avena sativa nuda L., var. NOS) were cultivated until flowering in pots in the greenhouse on a soil-sand mixture with normal fertilization. At this stage the plants were transferred to climate rooms at day temperatures of 12 C and 28 C, respectively. All other growth factors were held constant: 16 hr at 20,000 lux using mercury high vapor lamps, 70% relative humidity/day and night, and night temperatures of 12 C in both rooms.Plants were exposed to "CO2 at different stages after flowering. For this purpose a Plexiglas chamber (150 X 30 X 90 cm) was used. The evening before "C-feeding three pots were transferred into this chamber for adaptation at 12 C and 28 C, respectively. One hour before "COr-generation, CO,-free air was pumped through the chamber. While still in the dark, "CO2 was generated from 2 mc BaeCO, (51 mc/mmole). After "CO2 had become distributed uniformly within the chamber, the light source (20,000 lux) was switched on. After 2 hr of "COr-application, the nonassimilated "CO2 was evacuated from the chamber, ...

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“…The radioactivity of each fraction was measured by liquid scintillation counting in Aquasol. The ethanol-insoluble residue was combusted by the 02 flask method prior to counting (6). (3,4).…”

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confidence: 99%

Comparative Metabolism of 2,4-Dichlorophenoxyacetic Acid in Cotyledon and Leaf Callus from Two Varieties of Soybean

Davidonis¹,

Hamilton²,

Mumma³

1980

Plant Physiol.

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Only quantitative differences were observed in the metabolism of 11-4CJ2,4dichlorophenoxyacetic acid (2,4-D) by soybean cotyledon callus as influenced by variety (Acme and Amsoy), source of tissue (cotyledon, leaf and root) and age. All tissues metabolized 2,4-D to water-soluble (glycosides) and ether-soluble (primarily amino acid conjugates) metabolites.In young (3-to 4-week-old) Amsoy cotyledon or leaf callus tissue the free 2,4-D increased proportionately with the external 2,4-D concentration while in older (6-to 8-week-old) tissue the amino acid conjugates increased in this manner. Thus, in the older Amsoy tissue apparent regulation of the internal 2,4-D level (1.5-3.5 nmoles per gram fresh weight) was observed. In 3-or 6-week-old Acme cotyledon callus 2,4-D accumulated with an increase in the external 2,4-D concentration with no evidence for regulation of internal 2,4-D levels.We have previously studied the metabolism of the herbicide 2,4-dichlorophenoxyacetic acid in callus tissue cultures from soybean and several other plant species (2-5). The variations were mostly quantitative; however, major differences were observed between monocots and dicots. An Following incubation the tissue was collected by filtration through Whatman No. I paper (Buchner funnel), rinsed with cold distilled H20 and weighed. The tissue was homogenized with five times its weight of hot 95% ethanol. The homogenate was filtered and the residue washed extensively with 80% ethanol. The filtrate was concentrated to about 50 ml at 40 C on a rotating evaporator (aspirator), the pH adjusted to 3 (3 N H3PO4), and partitioned three times with equal volumes of diethyl ether. The aqueous portion was again partitioned three times with water-saturated 1-butanol. The aqueous concentrate from the 1 -butanol fraction was treated with Emulsin (U.S. Biochemical Corp.) as previously described (2). The diethyl ether fraction was further partiti6ned three times with 5% NaHCO3. The combined bicarbonate fraction was acidified (pH 3, 3 N H3P04), concentrated and reextracted with diethyl ether. The radioactivity of each fraction was measured by liquid scintillation counting in Aquasol. The ethanol-insoluble residue was combusted by the 02 flask method prior to counting (6).The fractions were examined by TLC on silica gel plates (Supelcosil 12A plus fluorescent indicator). Metabolites were cochromatographed with nonlabeled standards and located by autoradiography. The following solvent systems were used:

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Eine Schnellmethode zur Bestimmung von Tritium, Radiokohlenstoff und Radioschwefel in beliebigem organischem Probenmaterial mittels des Flüssigkeits‐Scintillations‐Zählers

Cited by 296 publications

References 11 publications

The Importance of Glucose in the Oxidative Metabolism of the Pregnant Uterus and Its Contents in Conscious Sheep With Some Preliminary Observations on the Oxidation of Fructose and Glucose by Fetal Sheep

The Importance of Glucose in the Oxidative Metabolism of the Pregnant Uterus and Its Contents in Conscious Sheep With Some Preliminary Observations on the Oxidation of Fructose and Glucose by Fetal Sheep

Influence of Temperature and Seed Ripening on the in-vivo Incorporation of ¹⁴CO₂ into the Lipids of Oat Grains (Avena sativa L.)

Comparative Metabolism of 2,4-Dichlorophenoxyacetic Acid in Cotyledon and Leaf Callus from Two Varieties of Soybean

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Eine Schnellmethode zur Bestimmung von Tritium, Radiokohlenstoff und Radioschwefel in beliebigem organischem Probenmaterial mittels des Flüssigkeits‐Scintillations‐Zählers

Cited by 296 publications

References 11 publications

The Importance of Glucose in the Oxidative Metabolism of the Pregnant Uterus and Its Contents in Conscious Sheep With Some Preliminary Observations on the Oxidation of Fructose and Glucose by Fetal Sheep

The Importance of Glucose in the Oxidative Metabolism of the Pregnant Uterus and Its Contents in Conscious Sheep With Some Preliminary Observations on the Oxidation of Fructose and Glucose by Fetal Sheep

Influence of Temperature and Seed Ripening on the in-vivo Incorporation of 14CO2 into the Lipids of Oat Grains (Avena sativa L.)

Comparative Metabolism of 2,4-Dichlorophenoxyacetic Acid in Cotyledon and Leaf Callus from Two Varieties of Soybean

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Influence of Temperature and Seed Ripening on the in-vivo Incorporation of ¹⁴CO₂ into the Lipids of Oat Grains (Avena sativa L.)