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31.
Regionally Selective Metabolic Effects of Hypoglycemia in Brain 总被引:12,自引:10,他引:2
Robert A. Ratcheson Ann C. Blank James A. Ferrendelli 《Journal of neurochemistry》1981,36(6):1952-1958
Abstract: Regional CNS levels of glucose reserves, glycolytic intermediates, and high-energy phosphate reserves were measured in insulin-treated, hypoglycemic rats and correlated with EEG activity. Intravenous administration of insulin to paralyzed, ventilated animals causes concomitant reduction of blood glucose levels and progressive abnormality and eventual loss of EEG activity. In all regions of brain examined, glucose and glycogen levels decrease until they are essentially depleted, and glucose-6-phosphate and fructose-1,6-biphosphate fall approximately 80%. Pyruvate levels decrease 50% in cerebral cortex and brain stem and a lesser amount in striatum, hippocampus, thalamus, and cerebellum. Lactate levels fall 50–60% in all regions except cerebellum, where no change is observed. ATP and phosphocreatine levels remain normal until the EEG is isoelectric, and then decrease in all regions except cerebellum. These results demonstrate that hypoglycemia does not have a uniform effect on brain glucose and energy metabolism, and cerebellum seems to be relatively protected. 相似文献
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R.M. Kostrzewa H. Fukushima A. Morrow P. Cohenour T. Hsi R.E. Lehr C.L. Blank 《Life sciences》1980,27(23):2245-2250
A new synthetic agent R, S-2-amino-1(2-amino-4, 5-dihydroxyphenyl) propane dihydrobromide, also referred to as α-methyl-6-aminodopamine (α-Me-6-ADA), has been found to produce acute (one day) and longer-term (seven day) depletion of norepinephrine (NE) levels in mouse brain and peripheral tissues. A 100 mg/kg dose of α-Me-6-ADA (i.v., free base) produced greater than 85% depletion of NE in the heart and spleen at one day and one week after treatment. Intracranially, α-Me-6-ADA (100 μg i.vtr.) depleted NE in the telencephalon and brain stem by 79% and 21% respectively at seven days. In addition DA was depleted by 45% in the ipsilateral striatum. The α-Me-6-ADA appears to have a relative selectivity for noradrenergic nerves, as an intracranial dose of 10 μg, which decreased NE in mouse whole brain by 52% at one day, failed to alter the DA content. These data suggest that α-Me-6-ADA may be a neurotoxin. 相似文献
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Ethanolamine plasmalogens (1-alk-1'-enyl-2-acyl-sn-glycero-3-phosphoethanolamines) of many tissues contain high levels of arachidonate at their 2-position, and in certain tissues have been implicated as possible donors of arachidonate required in the synthesis of prostaglandins and thromboxanes. In the present study, [3H]arachidonate-labeled phospholipids of HSDM1C1 cells, a cell line derived from a mouse fibrosarcoma, were examined to determine the donor of the arachidonic acid released upon bradykinin stimulation of the synthesis of PGE2. HSDM1C1 cells labeled with [3H]arachidonic acid for 24 hr in serum-free medium were used in most of the experiments and had the following distribution of label among the cellular lipids; phosphatidylcholine (33%), phosphatidylinositol (20%), diacyl-sn-glycero-3-phosphoethanolamine (15%), ethanolamine plasmalogen (15%), and less polar lipids )16%). Bradykinin treatment stimulated a rapid hydrolysis of [3H]arachidonate from the cellular lipids and conversion of the released acid to PGE2, which was secreted into the medium. The label was released predominantly from phosphatidylinositol and possibly from phosphatidylcholine with no detectable change in the labeling of diacyl- or 1-alk-1'-enyl-2-acyl-sn-glycero-3-phosphoethanolamine. The ethanolamine plasmalogens, therefore, do not appear to be involved in the stimulated release of arachidonate in the HSDM1C1 cells. Indomethacin blocked the bradykinin-stimulated synthesis of PGE2 and to a lesser degree inhibited the release of [3H]arachidonate from the cellular lipids into the medium. 相似文献
36.
delta5 desaturation of fatty acids in L-M cells 总被引:1,自引:0,他引:1
E N Lambremont T C Lee M L Blank F Snyder 《Biochemical and biophysical research communications》1978,80(4):813-818
L-M cells grown in a lipid-free medium containing 14C-labeled 9,12-linoleic acid incorporated most of this acid into glycerolipids as linoleic acid. Only a small amount (3%) was elongated to eicosadienoic acid. No Δ6 desaturation occurred. When the cells were incubated with 14C-labeled 8, 11, 14-eicosatrienoic acid, 22% of the activity was found in 5,8,11,14-eicosatetraenoic acid. Treatment of the cells for 24 hr with N-isopropylethanolamine, a choline analog, depressed this desaturation reaction to about 60% of control values. The identity of the tetraene product was established by two different chromatographic analyses of the fatty acid methyl esters. Location of the double bond at position C-5 was determined by ozonolysis and subsequent reduction of the ozonides to aldesters followed by gas-liquid chromatography. These results prove that L-M cells have a Δ5 desaturase and an elongation enzyme converting 18:2 to 20:2, but lack a Δ6 desaturase. 相似文献
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38.
BS Sabna Thankappan Bency Mahendran Ramasamy Muthusamy Gayathri Femil selta Daniel Raja Angayarkanni Jayaraman 《Probiotics and antimicrobial proteins》2021,13(4):993-1004
Probiotics and Antimicrobial Proteins - Gamma-aminobutyric acid (GABA) is a principal inhibitory neurotransmitter in the central nervous system and is produced by irreversible decarboxylation of... 相似文献
39.
Mitja Lu?trek Peter Lorenz Michael Kreutzer Zilliang Qian Felix Steinbeck Di Wu Nadine Born Bjoern Ziems Michael Hecker Miri Blank Yehuda Shoenfeld Zhiwei Cao Michael O. Glocker Yixue Li Georg Fuellen Hans-Jürgen Thiesen 《PloS one》2013,8(11)
Epitope-antibody-reactivities (EAR) of intravenous immunoglobulins (IVIGs) determined for 75,534 peptides by microarray analysis demonstrate that roughly 9% of peptides derived from 870 different human protein sequences react with antibodies present in IVIG. Computational prediction of linear B cell epitopes was conducted using machine learning with an ensemble of classifiers in combination with position weight matrix (PWM) analysis. Machine learning slightly outperformed PWM with area under the curve (AUC) of 0.884 vs. 0.849. Two different types of epitope-antibody recognition-modes (Type I EAR and Type II EAR) were found. Peptides of Type I EAR are high in tyrosine, tryptophan and phenylalanine, and low in asparagine, glutamine and glutamic acid residues, whereas for peptides of Type II EAR it is the other way around. Representative crystal structures present in the Protein Data Bank (PDB) of Type I EAR are PDB 1TZI and PDB 2DD8, while PDB 2FD6 and 2J4W are typical for Type II EAR. Type I EAR peptides share predicted propensities for being presented by MHC class I and class II complexes. The latter interaction possibly favors T cell-dependent antibody responses including IgG class switching. Peptides of Type II EAR are predicted not to be preferentially presented by MHC complexes, thus implying the involvement of T cell-independent IgG class switch mechanisms. The high extent of IgG immunoglobulin reactivity with human peptides implies that circulating IgG molecules are prone to bind to human protein/peptide structures under non-pathological, non-inflammatory conditions. A webserver for predicting EAR of peptide sequences is available at www.sysmed-immun.eu/EAR. 相似文献
40.
Laura David Peter Schwan Martin Lobedann Sven-Oliver Borchert Bastian Budde Maike Temming Mike Kuerschner Francisca Maria Alberti Aguilo Kerstin Baumarth Tobias Thüte Benjamin Maiser Andreas Blank Viktorija Kistler Nils Weber Heiko Brandt Martin Poggel Klaus Kaiser Karl Geisen Felix Oehme Gerhard Schembecker 《Biotechnology and bioengineering》2020,117(4):1024-1036
Continuous processing is the future production method for monoclonal antibodies (mAbs). A fully continuous, fully automated downstream process based on disposable equipment was developed and implemented inside the MoBiDiK pilot plant. However, a study evaluating the comparability between batch and continuous processing based on product quality attributes was not conducted before. The work presented fills this gap comparing both process modes experimentally by purifying the same harvest material (side-by-side comparability). Samples were drawn at different time points and positions in the process for batch and continuous mode. Product quality attributes, product-related impurities, as well as process-related impurities were determined. The resulting polished material was processed to drug substance and further evaluated regarding storage stability and degradation behavior. The in-process control data from the continuous process showed the high degree of accuracy in providing relevant process parameters such as pH, conductivity, and protein concentration during the entire process duration. Minor differences between batch and continuous samples are expected as different processing conditions are unavoidable due to the different nature of batch and continuous processing. All tests revealed no significant differences in the intermediates and comparability in the drug substance between the samples of both process modes. The stability study of the final product also showed no differences in the stability profile during storage and forced degradation. Finally, online data analysis is presented as a powerful tool for online-monitoring of chromatography columns during continuous processing. 相似文献