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1.
Phorbol myrystate acetate (PMA) activates nitroblue tetrazolium reduction in human polymorphs. The activation is inhibited by dibutyryl cyclic AMP, theophylline and phenylbutazone, but is not influenced by hydrocortisone in vitro, nor is it inhibited by leukocytes from patients treated with prednisone. Peptide analogues of Tuftsin also had no effect on this stimulatory activity. We conclude that the action of PMA on the nitroblue tetrazolium reduction is mediated through cyclic nucleotides.  相似文献   

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A Ginkgo biloba extract (Gbe) containing flavonoids, among other compounds, was tested for the release of activated oxygen species (O-2, H2O2, OH.) during the stimulation of human neutrophils (PMNs) by a soluble agonist. The extract slows down O2 consumption (respiratory burst) of stimulated cells by its inhibitory action on NADPH-oxidase, the enzyme responsible for the reduction of O2 to O-2. Consequently, superoxide anion (O-.2) and hydrogen peroxide (H2O2) production is significantly decreased when the PMNs stimulation is done in the presence of the extract at concentrations of 500, 250 and 125 micrograms/ml. Moreover, the hydroxyl radical generation (OH.) is very much decreased at concentrations as low as 15.6 micrograms Gbe/ml, which indicates that the extract also has free radical scavenging activity. Gbe is able at least to reduce very severely the activity of myeloperoxidase contained in neutrophils. This enzyme, secreted into the intra and extracellular medium, catalyzes the oxidation of chloride (Cl-) by H2O2 to yield strong oxidants (HOCl, chloramines) which are implicated in inflammatory processes.  相似文献   

4.
Summary A Ginkgo biloba extract (Gbe) containing flavonoids, among other compounds, was tested for the release of activated oxygen species ( , H2O2, OH.) during the stimulation of human neutrophils (PMNs) by a soluble agonist. The extract slows down O2-consumption (respiratory burst) of stimulated cells by its inhibitory action on NADPH-oxidase, the enzyme responsible for the reduction of O2 to . Consequently, superoxide anion ( ) and hydrogen peroxide (H2O2) production is significantly decreased when the PMNs stimulation is done in the presence of the extract at concentrations of 500, 250 and 125 g/ml. Moreover, the hydroxyl radical generation (OH.) is very much decreased at concentrations as low as 15.6 g Gbe/ml, which indicates that the extract also has free radical scavenging activity. Gbe is able at least to reduce very severel the activity of myeloperoxidase contained in neutrophils. This enzyme, secreted into the intra and extracellular medium, catalyzes the oxidation of chloride (Cl) by H2O2 to yield strong oxidants (HOCl, chloramines) which are implicated in inflammatory processes  相似文献   

5.
Riassunto Gli autori dimostrano la presenza di nucleoside fosforilasi nei granulociti neutrofili di essudato peritoneale sterile di cavia. L'attività enzimatica è distribuita quasi totalmente nella frazione solubile, presenta attività 10 volte più elevata sull'inosina che sulla guanosina, ha pH ottimale 7,8 e costante di Michaelis-Menten per l'inosina uguale a 3 · 10–5 M.  相似文献   

6.
Summary The temperature-dependence of some processes involved in the killing of sensitizedT. cruzi epimastigotes by human polymorphonuclear leukocytes (PMN) was determined. The rate of the reactions was related to the temperature of incubation according to the Arrhenius equation and the apparent energies of activation (Ea) were calculated. The Ea values separated these complex reactions into two groups: one with Ea of about 10 kcal/mol for the phagocytosis of the parasites and the release of lysosomal enzymes by PMN, and the other with Ea of about 22 kcal/mol for the cytotoxicity against sensitizedT. cruzi, the rate of oxygen consumption by PMN, and the lysis of the parasites with added hydrogen peroxide.This work was supported by research grants from CONICET and SUBCYT, Argentina, and UNDP/Word Bank/WHO Special Programme for Research and Training in Tropical Diseases. The author wish to thank Dr I. Reisin, Dr. A. Boveris and Dr M.M.E. de Bracco for their helpful discussion.  相似文献   

7.
Summary In leukocytes (PMN) of individuals with Swiss type acatalasemia, the rate of dehydroascorbate reduction is 4 times normal. This observation suggests that the protective function served by catalase in human PMN is supported by dehydroascorbate reductase.This work was aided by grants to L.S. and R.B. from the American Cancer Society (CH-30B), the Grand Bethel of Oregon, International Order of Job's Daughters, and to S.W. and H.A. by grant number 3.384.74 from the Swiss National Science Foundation.  相似文献   

8.
A variety of organoselenium compounds were originally described as antiinflammatory, antioxidant or glutathione-peroxidase-like agents, and as inhibitors of prostaglandin and leukotriene synthesis. Recently, the compounds have also been found to be inducers of interferon gamma and tumor necrosis factor in human peripheral blood leukocytes (PBL). We evaluated the effects of bis [2-(N-phenylcarboxamido)phenyl] diselenide and Ebselen; 2-phenyl-1,2-benzisoselenazol-3(2H)one, on the incorporation of tritiated thymidine into the DNA of PBL cultured in vitro. Both compounds were mitogenic and this effect was correlated with the expression of interleukin 2 receptor in T-lymphocytes. Therefore, we suggest that the selenoorganic compounds may induce mitogenic cytokines.  相似文献   

9.
Summary A variety of organoselenium compounds were originally described as antiinflammatory, antioxidant or glutathione-peroxidase-like agents, and as inhibitors of prostaglandin and leukotriene synthesis. Recently, the compounds have also been found to be inducers of interferon gamma and tumor necrosis factor in human peripheral blood leukocytes (PBL). We evaluated the effects of bis [2-(N-phenylcarboxamido)phenyl] diselenide and Ebselen®; 2-phenyl-1,2-benzisoselenazol-3(2H)one, on the incorporation of tritiated thymidine into the DNA of PBL cultured in vitro. Both compounds were mitogenic and this effect was correlated with the expression of interleukin 2 receptor in T-lymphocytes. Therefore, we suggest that the selenoorganic compounds may induce mitogenic cytokines.  相似文献   

10.
L Stankova  R Bigley  S R Wyss  H Aebi 《Experientia》1979,35(7):852-853
In leukocytes (PMN) of individuals with Swiss type acatalasemia, the rate of dehydroascorbate reduction is 4 times normal. This observation suggests that the protective function served by catalase in human PMN is supported by dehydroascorbate reductase.  相似文献   

11.
Summary The retinol analogues 13-cis-retinoic acid and ethyl etrinoate inhibit the mitogenic activity of phorbol myristate acetate and phytohemagglutinin on human lymphocytes. This inhibitory effect is greater against the stimulation with phorbol myristate acetate than with phytohemagglutinin.This work was supported by a grant from the National Cancer Institute of Canada. We would like to thank Hoffmann-La Roche, Canada, for providing the 13-cis-retinoic acid and the ethyl etrinoate.  相似文献   

12.
Riassunto Menadione in vitro inibisce l'attività fagocitaria di leucociti polinucleati in aerobiosi e in anaerobiosi. Vengono riportate prove sperimentali dalle quali risulta che l'effetto del menadione non è in rapporto con l'inibizione della glicolisi o con l'attività di trasporto di elettroni nella ossidazione dei piridinnucleotidi ridotti tramite una DT diaforasi.  相似文献   

13.
Summary The crucial functional groups of phorbol-12-myristate-13-acetate (PMA) are superimposable with those of the glucocorticoid cortisol in a unique manner which suggests a mechanism for PMA activity, i.e. the alkylation of a cortisol receptor.  相似文献   

14.
Summary Rabbit polymorphonuclear leukocytes (PMNs) were capped with territin-conjugated concanavalin A or ricin, and then allowed to phagocytose yeast cells. Phagocytic activity and lectin distribution were determined by ultrastructural morphometry. Capped PMNs were found to phagocytose as efficiently as control PMNs, and always to ingest the particles with a lectin-free portion of their plasma membrane. This clearly indicates that concanavalin A- and ricin-binding sites of the PMN membrane are not involved in the recognition and phagocytosis of yeast particles.  相似文献   

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Summary Feeding of excess vitamin A significantly increased the activity of -galactosidase and -glucuronidase without effecting the activity of acid and alkaline phosphatase in rat testicular homogenates. It is suggested that imbalance of vitamin A affects the normal process of spermatogenesis by altering the activity of lysosomal enzymes.Acknowledgments. The author is grateful to Dr C.M. Singh, I.V.R.I., Izatnagar and Dr L.N. Singh, for providing facilities and encouragement and to Prof. O. Isler, Hoffmann-La Roche, Basel, Switzerland, for the generous supply of retinyl acetate used in this work.  相似文献   

17.
In order to obtain a radioimmunoassay (RIA) technique for the measurement of human plasma myeloperoxidase (MPO), we purified the enzyme from polymorphonuclear granulocytes (neutrophils), and compared three methods of labeling it with125Iodine: chloramine T, lactoperoxidase, and an original technique of self labeling based on the ability of the enzyme to oxidize and bind125I in the presence of H2O2. The chloramine T technique produced a degraded protein, as well shown by a high non-specific binding of tracer to antibody. The lactoperoxidase technique did not succeed in labeling MPO with an adequate specific activity. In contrast, the self-labeling method gave a stable tracer with a specific activity of 23 Ci/gmg MPO (85 MBq), a satisfactory level of immunoreactivity, and a low-specific binding (3%). After labeling, purification of tracer was achieved by gel filtration chromatography in phosphate buffer (0.05 M; pH7) to which 0.1% poly-L-lysine was added. The labeled molecule remained stable for 40 days and could be used for RIA with a polyclonal antibody raised in rabbits.  相似文献   

18.
Summary Levels of collagenolytic activity produced by circulating polymorphonuclear leucocytes (PMN) of patients exposed to asbestos and patients with asbestosis were found to be similar to those of normal controls.Supported by MRC term grant MT-7310 and IRSSTQ. Reprint requests should be addressed to I.L.  相似文献   

19.
Zusammenfassung Die primäre Struktur von Ceruloplasmin im homozygotischen Morbus Wilson unterscheidet sich vom Normalen durch eine grössere Zahl von basischen Aminosäuren. Das abnorme Ceruloplasmin hemmt die Mitochondrienrespiration; freie Kupferionen haben dieselbe Wirkung, was möglicherweise durch Auflösung des Kupfer-Eiweiss-Komplexes erklärt werden kann.  相似文献   

20.
I C Ononogbu 《Experientia》1979,35(9):1156-1158
Very low density lipoprotein (VLDL) isolated from 3 healthy normolipidaemic subjects had a raised VLDL cholesterol to triglyceride ratio. The VLDL fractions gave 2 pre-beta-bands on agarose gel electrophoresis. Family study of the subjects appears to indicate sex linkage of this trait and a possible polygenic type of inheritance.  相似文献   

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