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1.
Repeated treatment of ethanol for 5 consecutive days has produced significant biochemical changes in the small intestine of the rat. The LDH and SDH were inhibited leading to deficient energy output from the glycolytic pathway and the Krebs cycle. The changes in ammonia metabolic profiles of intestine and blood indicate the presence of hyperammonemia. Enzymatic reactions associated with urea production and the levels of urea were increased. GS activity decreased explaining low levels of glutamine. These studies implicate PNC in producing hyperammonemia during ethanol treatment. 相似文献
2.
Studies on the existence of a pathway in liver and muscle for the conversion of glucose into glycogen without glucose 6-phosphate as an intermediate 总被引:1,自引:1,他引:0 下载免费PDF全文
Gabor J. Antony Indira Srinivasan Hollis R. Williams Bernard R. Landau 《The Biochemical journal》1969,111(4):453-459
Mixtures of (14)C-labelled glucose plus pyruvate were incubated either with rat diaphragm or slices of rat liver. Incorporation of glucose carbon into glycogen was compared with its incorporation into glucose 6-phosphate relative to the incorporation of pyruvate carbon into these metabolic products. There was no preferential incorporation of glucose carbon relative to pyruvate carbon into glycogen compared with glucose 6-phosphate in the liver slices, but there was in diaphragm. On the assumption that glucose 6-phosphate is a necessary intermediate in the conversion of pyruvate carbon into glycogen, this is evidence for the existence in muscle, but not in liver, of more than one pool of glucose 6-phosphate or of a pathway from glucose to glycogen without glucose 6-phosphate as an intermediate. Galactose carbon, relative to pyruvate carbon, was preferentially incorporated into liver glycogen, so that a substrate converted in liver into glycogen without glucose 6-phosphate as an intermediate could be detected by this approach. 相似文献
3.
Lipopolysaccharides of eight wild-type strains of the phototrophic bacterium Rhodospirillum tenue have been analyzed. All of the lipopolysaccharides are highly lipophilic. The compositions of preparations obtained by the phenol-water or by the phenol-chloroform-petroleum ether procedure are very similar. The polysaccharide moiety, obtained by mild acid hydrolysis of lipopolysaccharide, consists mainly of aldoheptoses: L-glycero-D-mannoheptose is present in all strains, whereas D-glycero-D-mannoheptose is an additional constituent in some strains. Galactosaminuronic acid and two unknown ninhydrin-positive components were detected in the lipopolysaccharides of six strains. Spermidine and putrescine are present in large amounts in a salt-like linkage in the lipopolysaccharides from three strains. 2-Keto-3-deoxyoctonate forms the linkage between the polysaccharide moiety and lipid A. The lipid A fraction contains all the glucosamine and all the D-arabinose present in the lipopolysaccharide. D-Arabinose is an invariable constituent of the lipid A from the Rhodopseudomonas tenue lipopolysaccharides investigated. The principal fatty acids are beta-hydroxycapric, myristic, and palmitic acids. The isolated R. tenue lipopolysaccharides (O-antigens) react with rabbit antisera prepared against homologous cells. The titers in passive hemagglutination are low, similar to those found with enterobacterial R-lipopolysaccharides. R. tenue O-antigens containing only L-glycero-D-mannoheptose and those containing both the L- and D-epimers of glycero-D-mannoheptose could not be differentiated by serological means. 相似文献
4.
Neurochemical consequences of repeated ethanol treatment on energy and ammonia metabolism were studied in different regions of rat brain. Energy production was decreased as indicated by lowered lactate dehydrogenase and succinate dehydrogenase activities with possible lacticacidimia. Transamination of alanine and aspartate increased while the deamination of glutamate decreased in all the regions of brain. The deamination of AMP was slightly elevated in cerebral cortex and brain stem while it was inhibited in cerebellum. Ammonia levels were persistently high, despite stepped up glutamine synthesis and ureogenesis. The synergistic action of ammonia during ethanol intoxication is envisaged. 相似文献
5.
Guinea pigs were given ascorbic acid orally in two doses; a low and a high dose. The tissue levels of ascorbic acid-2-sulphate was estimated in these animals after 15 days of feeding and a subsequent deprivation period of 15 days. The specific activity of the enzymes ascorbic acid sulphotransferase and ascorbic acid-2-sulphate sulphohydrolase was studied. During higher ascorbic acid intake, the activity of ascorbic acid sulphotransferase was increased, whereas ascorbic acid-2-sulphate sulphohydrolase showed a decreased activity. But when ascorbic acid intake was lowered or ceased, the activity of the above enzymes showed a reverse pattern. Possible reasons for the lack of antiscorbutic activity of ascorbic acid-2-sulphate in guinea pigs is discussed. 相似文献
6.
Annan Sudarsan Arun Kumar Gurusamy Umamaheswaran Ramamoorthy Padmapriya Jayaraman Balachandar Chandrasekaran Adithan 《Molecular biology reports》2013,40(2):1275-1281
Myocardial infarction (MI) is a complex multi-factorial, polygenic disorder which results from an interaction between a person’s genetic makeup and various environmental factors. Nitric oxide (NO), a potent vasodilator produced by endothelial cells, plays an important role in the regulation of blood pressure, regional blood flow and also inhibits platelet aggregation, vascular smooth muscle cell proliferation and leukocyte adhesion to vascular endothelium. Our aim was to analyze the association of NOS3 (endothelial nitric oxide synthase 3) 894G>T and ?786T>C gene polymorphisms and MI risk in the South Indian population. A total of 287 MI patients, 279 risk control patients and 321 healthy controls were recruited for the retrospective study. Genotyping was done using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). There was no significant association observed between NOS3 894G>T, ?786T>C polymorphisms and MI. A significant difference was observed in the distribution of GT genotype of the NOS3 894G>T polymorphism between the cases and the risk controls (p = 0.05) but the odds ratio (0.6) did not show risk for MI. The present study showed lack of association between NOS3 gene polymorphisms and MI in South Indian population. 相似文献
7.
Resurgent Na current flows as voltage-gated Na channels recover through open states from block by an endogenous open-channel blocking protein, such as the NaVβ4 subunit. The open-channel blocker and fast-inactivation gate apparently compete directly, as slowing the onset of fast inactivation increases resurgent currents by favoring binding of the blocker. Here, we tested whether open-channel block is also sensitive to deployment of the DIV voltage sensor, which facilitates fast inactivation. We expressed NaV1.4 channels in HEK293t cells and assessed block by a free peptide replicating the cytoplasmic tail of NaVβ4 (the “β4 peptide”). Macroscopic fast inactivation was disrupted by mutations of DIS6 (L443C/A444W; “CW” channels), which reduce fast-inactivation gate binding, and/or by the site-3 toxin ATX-II, which interferes with DIV movement. In wild-type channels, the β4 peptide competed poorly with fast inactivation, but block was enhanced by ATX. With the CW mutation, large peptide-induced resurgent currents were present even without ATX, consistent with increased open-channel block upon depolarization and slower deactivation after blocker unbinding upon repolarization. The addition of ATX greatly increased transient current amplitudes and further enlarged resurgent currents, suggesting that pore access by the blocker is actually decreased by full deployment of the DIV voltage sensor. ATX accelerated recovery from block at hyperpolarized potentials, however, suggesting that the peptide unbinds more readily when DIV voltage-sensor deployment is disrupted. These results are consistent with two open states in Na channels, dependent on the DIV voltage-sensor position, which differ in affinity for the blocking protein. 相似文献
8.
The methylerythritol phosphate (MEP) pathway of Plasmodium falciparum (P. falciparum) has become an attractive target for anti-malarial drug discovery. This study describes a kinetic model of this pathway, its use in validating 1-deoxy-d-xylulose 5-phosphate reductoisomerase (DXR) as drug target from the systemic perspective, and additional target identification, using metabolic control analysis and in silico inhibition studies. In addition to DXR, 1-deoxy-d-xylulose 5-phosphate synthase (DXS) can be targeted because it is the first enzyme of the pathway and has the highest flux control coefficient followed by that of DXR. In silico inhibition of both enzymes caused large decrement in the pathway flux. An added advantage of targeting DXS is its influence on vitamin B1 and B6 biosynthesis. Two more potential targets, 2-C-methyl-d-erythritol 2,4-cyclodiphosphate synthase and 1-hydroxy-2-methyl-2-(E)-butenyl 4-diphosphate synthase, were also identified. Their inhibition caused large accumulation of their substrates causing instability of the system. 相似文献
9.
Chaman Saini Anisuddin Siddiqui Venkatesh Ramesh Indira Nath 《PLoS neglected tropical diseases》2016,10(4)
Background
50% of leprosy patients suffer from episodes of Type 1/ reversal reactions (RR) and Type 2/ Erythema Nodosum Leprosum (ENL) reactions which lead to morbidity and nerve damage. CD4+ subsets of Th17 cells and CD25+FOXP3+ regulatory T cells (Tregs) have been shown to play a major role in disease associated immunopathology and in stable leprosy as reported by us and others. The aim of our study was to analyze their role in leprosy reactions.Methodology and Principle Findings
Quantitative reverse transcribed PCR (qPCR), flowcytometry and ELISA were used to respectively investigate gene expression, cell phenotypes and supernatant levels of cytokines in antigen stimulated PBMC cultures in patients with stable disease and those undergoing leprosy reactions. Both types of reactions are associated with significant increase of Th17 cells and associated cytokines IL-17A, IL-17F, IL-21, IL-23 and chemokines CCL20, CCL22 as compared to matching stable forms of leprosy. Concurrently patients in reactions show reduction in FOXP3+ Treg cells as well as reduction in TGF-β and increase in IL-6. Moreover, expression of many T cell markers, cytokines, chemokines and signaling factors were observed to be increased in RR as compared to ENL reaction patients.Conclusions
Patients with leprosy reactions show an imbalance in Th17 and Treg populations. The reduction in Treg suppressor activity is associated withhigherTh17cell activity. The combined effect of reduced TGF-β and enhanced IL-6, IL-21 cytokines influence the balance between Th17 or Treg cells in leprosy reactions as reported in the murine models and autoimmune diseases. The increase in Th17 cell associated cytokines may contribute to lesional inflammation. 相似文献10.