Effects of 2,4-D on Metabolism of 14C-Glucose in Plant Tissues

Weed Science ◽  
1971 ◽  
Vol 19 (3) ◽  
pp. 248-253
Author(s):  
I. Y. Mostafa ◽  
S. C. Fang
Keyword(s):  
Time Course ◽  
Pentose Phosphate ◽  
Insoluble Residue ◽  
Opposite Pattern ◽  
Corn Roots ◽  
Pea Roots ◽  
Time Course Study ◽  
Acid Pathway ◽  
Dichlorophenoxy Acetic Acid

A time course study on the in vitro effect of 10–4 M (2,4-dichlorophenoxy)acetic acid (2,4-D) on the metabolism and incorporation of specific 14C-labeled glucose into pea (Pisum sativum L., var. Alaska) and corn (Zea mays L., var. Golden Cross) tissues showed a preferential release of C-1 as CO2 which was affected by 2,4-D. The glucuronic acid pathway was stimulated greatly in pea roots and slightly in corn stems; it was inhibited in corn roots. The pentose phosphate pathway was affected in an opposite pattern. The incorporation of both labeled carbon atoms into alcohol-insoluble residue was also affected by 2,4-D. The degree of effect, however, varied from pea to corn and from roots to stems. Analysis of the alcohol-soluble fraction revealed different effects of 2,4-D on labeling of some of the amino acids, an increase in fructose content, and an accumulation of malic acid.

scholarly journals The regulation of lipogenesis in vivo in the lactating mammary gland of the rat during the starved-refed transition. Studies wtih acarbose, a glucosidase inhibitor

1987 ◽  
Vol 242 (1) ◽  
pp. 235-243 ◽  
Author(s):  
S W Mercer ◽  
D H Williamson
Keyword(s):  
Mammary Gland ◽  
Time Course ◽  
Chow Diet ◽  
Glucosidase Inhibitor ◽  
Lactating Mammary Gland ◽  
Phosphofructokinase Activity ◽  
Time Course Study ◽  
Fructose 1,6 Bisphosphate

Depression of carbohydrate digestion by oral administration of acarbose, a glucosidase inhibitor, led to a 75% inhibition of the re-activation of lipogenesis in vivo in the mammary gland of 18 h-starved lactating rats refed with 5 g of chow diet. Rates of [1-14C]glucose incorporation in vitro into lipid and CO2 in mammary-gland acini isolated from refed animals were elevated compared with acini from starved rats, but acarbose treatment completely prevented this stimulation. Gastric intubation of glucose led to a large stimulation of lipogenesis in the mammary gland of starved lactating rats, similar to that induced by refeeding with chow diet; this was dependent on the amount of glucose given and the time elapsed between glucose administration and injection of 3H2O for the measurement of lipogenesis. The switch-on of lipogenesis in the mammary gland of starved lactating rats, by refeeding or by intubation of glucose, was associated with a decrease in the ratio of [glucose 6-phosphate]/[fructose 1,6-bisphosphate] in the gland, indicative of an increase in phosphofructokinase activity. A time-course study revealed that the ratio decreased rapidly over the first 30 min of chow refeeding, after which a large surge in lipogenesis was seen. Acarbose, given 25 min after the onset of refeeding, led to a stepwise increase in the ratio, in parallel with the observed decrease in lipogenic activity. It is concluded that the control of lipogenesis in the mammary gland is closely linked to the availability of dietary carbohydrate. An important site of regulation of lipogenesis in the gland appears to be at the level of phosphofructokinase. A possible role of insulin in the regulation of phosphofructokinase activity, and the acute modulation of insulin-sensitivity in the gland during the starved-refed transition, are discussed.

scholarly journals Reduced Latency in the Metastatic Niche Contributes to the More Aggressive Phenotype of LM8 Compared to Dunn Osteosarcoma Cells

Sarcoma ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Matthias J. E. Arlt ◽  
Ingo J. Banke ◽  
Josefine Bertz ◽  
Ram Mohan Ram Kumar ◽  
Roman Muff ◽  
...  
Keyword(s):  
Time Course ◽  
Kidney Tissue ◽  
Experimental System ◽  
Osteosarcoma Cells ◽  
Primary Tumors ◽  
Liver And Kidney ◽  
Time Course Study ◽  
Cell Dormancy

Metastasis is the major cause of death of osteosarcoma patients and its diagnosis remains difficult. In preclinical studies, however, forced expression of reporter genes in osteosarcoma cells has remarkably improved the detection of micrometastases and, consequently, the quality of the studies. We recently showed that Dunn cells equipped with alacZreporter gene disseminated from subcutaneous primary tumors as frequently as their highly metastatic subline LM8, but only LM8 cells grew to macrometastases. In the present time-course study, tail-vein-injected Dunn and LM8 cells settled within 24 h at the same frequency in the lung, liver, and kidney of mice. Furthermore, Dunn cells also grew to macrometastases, but, compared to LM8, with a delay of two weeks in lung and one week in liver and kidney tissue, consistent with prolonged survival of the mice. Dunn- and LM8-cell-derived ovary and spine metastases occurred less frequently.In vitro, Dunn cells showed less invasiveness and stronger contact inhibition and intercellular adhesion than LM8 cells and several cancer- and dormancy-related genes were differentially expressed. In conclusion, Dunn cells, compared to LM8, have a similar capability but a longer latency to form macrometastases and provide an interesting new experimental system to study tumor cell dormancy.

Suitability of Glomus intraradices in vitro produced spores and root segment inoculum for the establishment of a mycorrhizosphere in an experimental microcosm

2001 ◽  
Vol 79 (8) ◽  
pp. 879-885
Author(s):  
M Filion ◽  
M St-Arnaud ◽  
C Guillon ◽  
C Hamel ◽  
S H Jabaji-Hare
Keyword(s):  
Microbial Ecology ◽  
Time Course ◽  
Glomus Intraradices ◽  
Mycorrhizal Fungus ◽  
Experimental System ◽  
Arbuscular Mycorrhizal ◽  
Root Segment ◽  
Soil Conditions ◽  
Time Course Study

Various experimental systems have been developed to study the mycorrhizosphere. In this study, a microcosm experimental system was constructed and optimized to simulate the environments of the mycorrhizosphere: the rhizosphere, the mycosphere, and the bulk soil, using beans (Phaseolus vulgaris L.) as host plants. We investigated, in a time-course study, the effect of axenically in vitro produced spore inoculum and root segment inoculum of the arbuscular mycorrhizal fungus, Glomus intraradices Schenck & Smith, on extraradical mycelium development, rapidity of mycorrhizal colonization, and plant growth under nonsterile soil conditions. Three concentrations of in vitro produced spores and three concentrations of root segment inoculum produced from open pot cultures were used. The two highest concentrations of spores used as inoculum resulted in faster and more abundant colonization than when root segments were used. A significant correlation was obtained between hyphal densities present in the rhizosphere and mycosphere compartments, and the amount of spore inoculum used. The densities of roots in the rhizosphere compartment and hyphae in the rhizosphere and mycosphere compartments were comparable with field-grown plants; thus, the system realistically mimics a natural mycorrhizosphere. The use of the microcosm described in this study, in combination with the in vitro produced spore inoculum of G. intraradices, represents an experimental approach well adapted for studying the microbial ecology of the mycorrhizosphere.Key words: AMF, microbial ecology, inoculum, mycorrhiza, mycorrhizosphere.

AVP and dDAVP in rabbit cortical collecting tubule: a comparative time-course study

1990 ◽  
Vol 258 (1) ◽  
pp. R99-R103
Author(s):  
M. Leite ◽  
W. N. Suki
Keyword(s):  
Time Course ◽  
Cell Types ◽  
Receptor Activation ◽  
Osmotic Water ◽  
Significant Difference ◽  
Time Course Study ◽  
Time Required ◽  
Collecting Tubules ◽  
Different Cell Types

The V2-selective analogue of arginine vasopressin (AVP), dDAVP, has been used to distinguish between the effects of V1- and V2-receptor activation by AVP in different cell types of the kidney. Based on studies showing different effects of AVP and dDAVP on prostaglandin secretion, and also on cytosolic Ca2+, we designed a comparative time-course study of both agonists on rabbit microdissected cortical collecting tubules (CCT) microperfused in vitro at 38 degrees C. Plots of the effects of AVP (10 microU/ml or 2.2 x 10(-11) M and 100 microU/ml or 2.2 x 10(-10) M) and dDAVP (10 microU/ml or 0.8 x 10(-11) M) on osmotic water permeability (Pf) at comparable antidiuretic activities, revealed an increase of Pf that was maintained for as long as 170 min of hormone exposure. Also the magnitude of increase in Pf and the time required to achieve the more sustained phase of response were comparable, with no significant difference between the two agonists. These results clearly demonstrate a stable response of rabbit CCT to AVP and dDAVP at physiological temperature, and they reveal no evidence for a difference between the native hormone AVP and its V2 selective analogue on the net hydrosmotic response of the CCT.

Characterization of in vitro protein oxidation using mass spectrometry: A time course study of oxidized alpha-amylase

2013 ◽  
Vol 530 (1) ◽  
pp. 23-31 ◽  
Author(s):  
André M.N. Silva ◽  
Susana L. Marçal ◽  
Rui Vitorino ◽  
Maria R.M. Domingues ◽  
Pedro Domingues
Keyword(s):  
Mass Spectrometry ◽  
Protein Oxidation ◽  
Time Course ◽  
Alpha Amylase ◽  
Time Course Study ◽  
Vitro Protein

Longitudinal in vivo and in vitro time-course study of chronic cerebrovasospasm in the rabbit basilar artery

1991 ◽  
Vol 14 (3) ◽  
pp. 215-219 ◽  
Author(s):  
Peter Vorkapic ◽  
John A. Bevan ◽  
Rosemary D. Bevan
Keyword(s):  
Basilar Artery ◽  
Time Course ◽  
Time Course Study

scholarly journals 13C tracer analysis identifies extensive recycling of endogenous CO2 in vivo

2021 ◽  
Author(s):  
Likun Duan ◽  
Daniel E. Cooper ◽  
Grace Scheidemantle ◽  
Jason W. Locasale ◽  
David G. Kirsch ◽  
...  
Keyword(s):  
Time Course ◽  
Cultured Cells ◽  
Tca Cycle ◽  
Data Interpretation ◽  
Carboxylase Activity ◽  
Intact Cells ◽  
Time Course Study ◽  
Metabolic Activities

Abstract13C tracing analysis is increasingly used to monitor cellular metabolism in vivo and in intact cells, but data interpretation is still the key element to unveil the complexity of metabolic activities. We have performed [U-13C]-glucose and [U-13C]-glutamine tracing in sarcoma-bearing mice (in vivo) and in cancer cell lines (in vitro). 13C enrichment of metabolites in cultured cells and tissues was determined by liquid chromatography coupled with high-resolution mass spectrometer (LC-HRMS). As expected, citrate M+2 or M+4 is the dominant mass isotopologue in vitro. However, citrate M+1 was unexpectedly the dominant isotopologue in mice receiving [U-13C]-glucose or [U-13C]-glutamine infusion. One plausible explanation is that 13CO2 produced from the oxidation of 13C tracers in vitro is negligible due to the dilution of HCO3- supplemented to cell culture when sodium bicarbonante is used and diffusible volume of CO2 in the culture incubator, while endogenous 13CO2 in vivo is substantial and is fixed into the TCA cycle, purine, and serine, resulting in M+1 isotopologues. A time course study shows the generation of high abundance citrate M+1 early in plasma, which may serve as a potent non-invasive biomarker of tissue pyruvate carboxylase activity. Altogether, our results show that recycling of endogenous CO2 is substantial in vivo and provides important insights into the experimental design and data interpretation of 13C tracing assays.

scholarly journals Synthesis of Hemoglobin Abraham Lincoln (β 32 leu → pro)

Blood ◽  
1974 ◽  
Vol 43 (5) ◽  
pp. 657-664 ◽  
Author(s):  
George R. Honig ◽  
R. George Mason ◽  
Loyda N. Vida ◽  
Mir Shamsuddin
Keyword(s):  
Time Course ◽  
Specific Activity ◽  
Abraham Lincoln ◽  
Rapid Destruction ◽  
Time Course Study ◽  
Chain Synthesis ◽  
Globin Chain Synthesis ◽  
Linear Manner ◽  
Β Chain

Abstract Globin chain synthesis was studied in vitro with reticulocytes from a patient heterozygous for Hb Abraham Lincoln, an unstable beta chain variant. Synthesis of α-chains by the reticulocytes exceeded total β-chain synthesis, and a substantial fraction (about 16%) of radioactivity incorporated into globin was recovered from the cells as uncombined α subunits. In a time-course study, the ratio of α : β-chain specific activity was found to increase progressively in a nearly linear manner, suggesting that a fraction of newly synthesized β-chains had undergone rapid destruction. The specific activity of the abnormal β-chain was nearly three times that of βA. The rate of synthesis of the β-chain of Hb Abraham Lincoln appeared to be approximately half that of the β-chain of Hb A.

Hormonal control of casein synthesis in organ culture of the bovine lactating mammary gland

1982 ◽  
Vol 49 (3) ◽  
pp. 387-398 ◽  
Author(s):  
Arieh Gertler ◽  
Anat Weil ◽  
Nava Cohen
Keyword(s):  
Mammary Gland ◽  
Time Course ◽  
Dominant Role ◽  
Significant Inhibition ◽  
Hormonal Control ◽  
Maximal Effect ◽  
Lactating Mammary Gland ◽  
Time Course Study ◽  
Casein Synthesis

SUMMARYExplants from lactating bovine mammary gland were culturedin vitroin serum-free medium through 1–9 d. Casein synthesis was determined by [32P] incorporation into newly synthesized Ca rennin precipitable fraction. High correlation (γ = 0·98) was found between incorporation of [32P] and [3H]amino acids in explants cultured under different hormonal regimes, thus indicating that post-translational phosphorylation is not a rate-limiting step in casein synthesis.Hormonal effects on casein synthesis were studied by supplementing the incubating medium with insulin (I), prolactin (PRL), cortisol (F), thyroxine (T4) and triiodothyronine (T3). It was found that both PRL and I were required absolutely for maximal synthesis and almost maximal effect was achieved with 50 ng/ml. The effect of F was less clear, but some increase was achieved at the 200–1000 ng/ml range. T4and T3did not affect casein synthesis at a range of 10-11–10-7M while a significant inhibition was observed at 2 × 10-5M. A time-course study of casein synthesis further substantiated the dominant role of PRL in maintenance or even elevation of the initial rate of casein synthesis in the explants, through the first 4 d of incubation.

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