Anti-CD3 activation of human CD4+ T cells increases expression of the intracellular beta-endorphin endopeptidase (IDE/gamma-EpGE).

In this study, increased expression of an endopeptidase hydrolyzing beta-endorphin (beta-Ep) to gamma-endorphin (gamma-Ep, beta-Ep1-17) was observed upon immobilized anti-CD3 stimulated activation of human peripheral blood CD4+ T cells (hCD4+ T cells). Although freshly isolated hCD4+ T cells are devoid of significant beta-Ep endopeptidase activity ( < 0.1 nmol h(-1) 10(6) cells (-1)), activation of these cells with immobilized anti-CD3 results in a time dependent appearance of beta-Ep endopeptidase activity which reaches a maximal value of 17.

Increased expression of an endopeptidase (gamma-EGE/IDE) hydrolyzing beta-endorphin during differentiation and maturation of bone marrow macrophages.

The presence and regulated expression of peptidase activity is a powerful mechanism with the potential to terminate or alter receptor recognition, cell membrane signal transduction, and physiological responses of immune cells to exogenous opioid peptides. In this study, the expression of an endopeptidase that hydrolyzes beta-endorphin to gamma-endorphin and other peptide products was investigated during in vitro differentiation and maturation of recombinant granulocyte-macrophage colony-stimulating factor (rGM-CSF) -derived, bone marrow-derived macrophages. In freshly isolated intact isolated mouse bone marrow cells the rate of beta-endorphin hydrolysis is undetectable (<0.

Measurement of gluconeogenesis and pyruvate recycling in the rat liver: a simple analysis of glucose and glutamate isotopomers during metabolism of [1,2,3-(13)C3]propionate.

Simple equations that relate glucose and glutamate 13C-NMR multiplet areas to gluconeogenesis and pyruvate recycling during metabolism of [1,2,3-(13)C3]propionate are presented. In isolated rat livers, gluconeogenic flux was 1.2 times TCA cycle flux and about 40% of the oxaloacetate pool underwent recycling to pyruvate prior to formation of glucose.

A secreted peptidase involved in T cell beta-endorphin metabolism.

Beta-endorphin metabolism by CD4+ and CD8+ T cells, and the thymoma cell line, EL4, was investigated. In all three cell types, extracellular beta-endorphin was metabolized exclusively by a secreted, metal-dependent, thiol peptidase. The enzyme activity is expressed constitutively in EL4 cells and following activation of CD4+ and CD8+ T cells with anti-CD3 antibody.

In vivo effects of lipopolysaccharide on hepatic free-NAD(P)(+)-linked redox states and cytosolic phosphorylation potential in 48-hour-fasted rats.

This study was performed to determine the magnitude and time of onset of in vivo changes in hepatic bioenergetics in response to a sublethal dose of lipopolysaccharide (LPS), a bacterial endotoxin. Male rats (48-hour-fasted) were administered an intraperitoneal injection of LPS (5 mg/kg body weight) or vehicle alone, and the livers were freeze-clamped 5, 30, or 180 minutes or 24 hours later. Liver tissue was extracted with perchloric acid, and the metabolites necessary to calculate NAD(+)- and NADP(+)-linked redox states and the cytosolic phosphorylation potential were measured.

Expression of G alpha i2 mimics several aspects of LPS priming in a murine macrophage-like cell line.

Priming of macrophages with low concentrations of lipopolysaccharide (LPS) enhances the ability of substances that act through heterotrimeric G proteins to stimulate immune cell functions. Although LPS-induced alterations in the expression and functions of G proteins of the alpha i family have been reported in hematopoietic cells, their effects on subsequent steps in LPS priming of macrophages have not been defined. To study the role of G alpha i2 in priming of macrophages by LPS, we expressed a mutant, activated form of alpha i2 (alpha i2Q205L) in P388D1 cells, and compared its effects on PAF-dependent C alpha signalling and arachidonic acid release to those in cells treated with LPS.

[[omega-(Heterocyclylamino)alkoxy]benzyl]-2,4-thiazolidinediones as potent antihyperglycemic agents.

A series of [(ureidoethoxy)benzyl]-2,4-thiazolidinediones and [[(heterocyclylamino)alkoxy]-benzyl]-2,4-thiazolidinediones was synthesized from the corresponding aldehydes. Compounds from the urea series, exemplified by 16, showed antihyperglycemic potency comparable with known agents of the type such as pioglitazone and troglitazone (CS-045). The benzoxazole 49, a cyclic analogue of 16, was a very potent enhancer of insulin sensitivity, and by modification of the aromatic heterocycle, an aminopyridine, 37, was identified as a lead compound from SAR studies.

Orientation-conserved transfer of symmetric Krebs cycle intermediates in mammalian tissue.

Metabolism of [2-13C]-, [3-13C]-, and [1,2,3-13C]propionate in perfused rat livers and [2-13C]-acetate in perfused rat hearts has been examined in tissue extracts by 13C NMR. Label from [2-13C]-propionate was preferentially incorporated into the C2 carbon of lactate, alanine, and aspartate in liver tissue while label from [3-13C]propionate appeared preferentially in the C3 carbon of those same molecules. These data suggest that 13C may not be completely randomized in the symmetric citric acid cycle intermediates succinate and fumarate as is normally assumed but that some fraction of those intermediates may be transferred between enzymes in this span of the cycle with conservation of spatial orientation, consistent with recent results obtained in yeast [Sumegi et al.

Methionine enkephalin is hydrolyzed by aminopeptidase N on CD4+ and CD8+ spleen T cells.

Exogenous methionine enkephalin incubated with CD4+ or CD8+ T cells purified from murine spleen is metabolized primarily, if not exclusively, by aminopeptidase N (aminopeptidase M, EC 3.4.11.

A method for obtaining 13C isotopomer populations in 13C-enriched glucose.

13C NMR analysis of 13C-enriched glucose containing multiple isotopomers is hampered by chemical shift similarities of several carbon resonances and by the presence of two anomeric forms. A convenient and quantitative method of enzymatically oxidizing glucose to gluconate in tissue and perfusate extracts is presented. The six carbon resonances of the resulting 13C-enriched gluconate are fully resolved at high pH, thereby allowing a determination of the fractional population of each 13C isotopomer by 13C NMR.

Methionine enkephalin metabolism by murine macrophage ectopeptidase(s).

Ectopeptidases which hydrolyze opioid and other neuropeptides have been identified in brain, kidney and intestine. In this study, identification of the enzymes metabolizing the opioid peptide methionine enkephalin (YGGFM) in murine macrophages was undertaken. Incubation of methionine enkephalin with intact murine peritoneal macrophages results in five products identified as Y, F, FM, GFM and GGFM by amino acid analysis and peptide microsequencing after fractionation by HPLC.

Endotoxin stimulation of liver parenchymal cell phosphofructokinase activity requires nonparenchymal cells.

The rate of carbohydrate flux through phosphofructokinase (measured as the rate of [3-3H]glucose detritiation) was increased fourfold in rat liver parenchymal cells incubated with conditioned medium from lipopolysaccharide-stimulated adherent liver non-parenchymal cells. The rate was not affected in parenchymal cells incubated either with lipopolysaccharide directly or with conditioned medium from non-stimulated non-parenchymal cells. The stimulation of carbohydrate flux through phosphofructokinase by conditioned medium was not duplicated by peptide cytokines known to be released by lipopolysaccharide-activated liver non-parenchymal cells (interleukin-1, interleukin-6, tumor necrosis factor-alpha, and transforming growth factor-beta) or platelet activating factor.

Pertussis toxin and H-7 distinguish mechanisms involved in eicosanoid release from lipopolysaccharide-primed macrophages. Eicosanoid release from lipopolysaccharide-primed macrophages.

Release of eicosanoids is an important response of macrophages to inflammation and bacterial infection. At low concentrations, bacterial lipopolysaccharide (1-2 micrograms/ml) fails to stimulate eicosanoid release in resident peritoneal macrophages but primes the macrophages for a greatly enhanced release of eicosanoids on stimulation with the calcium ionophore A23187 (0.1 microM) or with phorbol 12-myristate 13-acetate (50 nM), an activator of protein kinase C.

Endotoxin increases the liver fructose 2,6-bisphosphate concentration in fasted rats.

Following endotoxin administration to fasted rats, the liver fructose 2,6-bisphosphate level is significantly increased within 1 hr, is elevated 2.3-fold by 3 hrs, and remains elevated 2 to 3-fold for at least 24 hrs. This increase in the potent allosteric activator of phosphofructokinase occurs when there is no change in the liver Glc 6-P, glycogen or cAMP concentrations, or in the activities of phosphoenolpyruvate carboxykinase or pyruvate kinase.

Dehydroisoandrosterone prevention of autoimmune disease in NZB/W F1 mice: lack of an effect on associated immunological abnormalities.

The effect of dietary dehydroisoandrosterone (DHA) on several immunological abnormalities associated with the development of systemic lupus erythematosus in New Zealand Black/New Zealand White F1 (NZB/W) female mice was examined. Despite the extraordinary benefits in prolonged survival and decreased synthesis of antibodies to double-stranded DNA obtained by adding DHA (0.4% w/v) to the diet fed to these mice (Lucas et al.

Wheelchair obstacle course performance in right cerebral vascular accident victims.

The initial experiment of this paper investigated the role of hemispatial neglect in wheelchair-related accidents of right-hemisphere stroke victims. Twelve subjects with and 12 subjects without neglect of left space drove their wheelchairs through an obstacle course. Two types of obstacle course errors were evaluated: direct hits and sideswipes.

Liver composition and lipid metabolism in NZB/W F1 female mice fed dehydroisoandrosterone.

The beneficial effects obtained with dehydroisoandrosterone (DHA) feeding in the treatment of murine systemic lupus erythematosus are similar to those obtained with caloric restriction or with dietary manipulation of essential fatty acid availability. In this study, the fatty acid composition of selected tissues was examined in NZB/W F1 mice fed a diet containing 0.4% DHA.

Immunological properties of chemically produced fragments of rye grass pollen extract.

Two fragment pools, one of MW greater than 10,000 and the other of MW between 1,000 and 10,000, were prepared by the sequential treatment of rye grass pollen extract with cyanogen bromide (cleavage at Met-X) and 2-nitro-5-thiocyanobenzoic acid (cleavage at X-Cys). Electrophoretic analysis of the two pools showed that none of the major components of the whole extract remained intact. Characterisation of the two fragment pools by radioimmunoassay showed that whilst they both lost the ability to bind to human anti-rye IgE antibodies, they largely retained their reactivity towards both human and mouse anti-rye IgG antibodies.

Retained T-cell reactivity of rye grass pollen extract following cleavage with cyanogen bromide and nitrothiocyanobenzoic acid.

Rye grass pollen extract was fragmented by sequential treatments with cyanogen bromide and 2-nitro-5-thiocyanobenzoic acid, and a fraction containing fragments of molecular weight greater than 10,000 Mr was isolated. The in vitro reactivity of the extract with specific IgE was extensively reduced by fragmentation. Less reduction in activity was shown either by skin testing or by inhibition of an extract-specific IgG-binding assay.

Hormonal regulation of L-type pyruvate kinase in rat liver cells in culture.

An immortalized rat liver cell line (RLC) expresses two isozymes of pyruvate kinase, the adult liver or L-type isozyme and an M-type isozyme presumed to be the M2-type. In RLC cells incubated in serum-free medium, the addition of 0.1 microM insulin maintained the initial level of L-type pyruvate kinase when it was high and induced the L-type isozyme when it was low.

Physicochemical and immunochemical characterization of allergenic proteins from rye-grass (Lolium perenne) pollen prepared by a rapid and efficient purification method.

Three fractions of rye-grass (Lolium perenne) pollen extract have been isolated by preparative isoelectric focusing (i.e.f.