Wyniki wyszukiwania - Biblioteka Nauki

1

Antileukotriene treatment and allergic rhinitis-related cough in guinea pigs

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Brozmanova M. , Plevkova J. , Bartos V. , Plank L. , Tatar M.

Journal of Physiology and Pharmacology. Supplement

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2005

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tom 56

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nr 4

21-30

EN

Experimental allergic rhinitis produces enhanced cough response in awake guinea pigs. Leukotriene receptor antagonists, as anti-inflammatory agents, have been effective in treatment of asthma and allergic rhinitis to inhibit the early and late allergic response. In the present study, we evaluated the effect of montelukast (Singulair, Merck, USA) on the cough reflex in an experimental model of allergen-induced rhinitis in guinea pigs. Guinea pigs (n=16) were sensitized with intraperitoneal ovalbumin (OVA). The animals were then used to develop a model of allergic rhinitis by repeated intranasal instillation of 0.5% OVA at weekly intervals for 8 weeks. Allergic rhinitis was evaluated from the occurrence of typical clinical symptoms including sneezing, conjuctival and nasal secretion, or nasal acoustic phenomenon. Between the 6th and 8th nasal challenge (NCh) the animals (n=8) were treated daily for 14 days with oral montelukast (10mg/kg). Cough was induced by citric acid aerosol inhalation in gradually increasing concentration (0.05-1.6 M) and was evaluated before sensitization and then after the 1st, 6th, and 8th nasal challenge when rhinitic symptoms were most conspicuous. The intensity of cough was significantly increased after the first and repeated nasal OVA challenges, and reduced after the 8th NCh that was preceded with montelukast treatment [9(6-14) vs. 16.5(14-22) vs. 25.5(23-42) vs. 8.5(8-13); P=0.0003]. We conclude that antileukotriene therapy suppresses the stimulating effect of experimental allergic rhinitis on the chemically-induced cough in awake guinea pigs.

2

Functional analysis of eicosanoids from white blood cells in sepsis and SIRS

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Baenkler M. , Leykauf M. , John S.

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nr 12

25-33

EN

Sepsis and SIRS are affections with major alterations in inflammatory activity. The impact of prostaglandins (PG) and leukotrienes (LT) produced from white blood cells (WBC) in this context is not completely understood. Thirty nine patients with sepsis or SIRS were investigated in comparison to 10 healthy controls. WBC were collected and separately exposed to arachidonic acid (AA) or to nothing else. After centrifugation, the generated PGE2 and LTCDE4 with or without stimulation were measured in the supernatant. LT-levels were significantly higher during sepsis/SIRS than in controls whereas PG-levels of patients were decreased to those of controls in basic condition. The relation between the level with and without stimulation showed a significant higher ratio in PG in contrast to LTs. The survivor’s ratio in LT levels was significantly higher than that of non-survivors, which did not differ from controls. Generation of LT from WBC is enhanced during sepsis/SIRS, but LT generation after stimulation only in survivors but not in non-survivors. This inability of WBC to generate LT during sepsis in non-survivors could be predictive regarding the outcome of sepsis/SIRS and may be part of the “immunoparalysis” seen during sepsis in association with bad outcome.

3

Pharmacological inhibition of leukotriene biosynthesis: effects on the heart conductance

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Sanak M. , Dropinski J. , Sokolowska B. , Faber J. , Rzeszutko M. , Szczeklik A.

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nr 1

53-58

EN

Leukotrienes are lipid mediators produced via 5-lipooxygenase pathway of arachidonic acid. At least two cysteinyl-leukotrienes receptors are highly expressed in the heart, including the conduction system. Coronary angiography or angioplasty is accompanied by release of cysteinyl leukotrienes into coronary circulation and into urine. We tested the hypothesis that inhibition of leukotrienes biosynthesis would affect the conductance system function. In a double-blind placebo controlled study, patients with stable angina undergoing elective coronary catheterization or angioplasty were randomly assigned to 48 hrs treatment with a 5-lipoxgenase inhibitor (n=54) or placebo (n=49). ECG Holter recording was carried out for 24 hrs before and after the procedure and urinary leukotriene E4 measurements were done. Inhibition of 5-lipoxygenase caused 26% reduction of urinary leukotriene E4, associated with: 1) decrease in heart rate by about 7%, 2) enhanced heart rate variability; 3) protection against depressions in atrioventricular conductance and ventricular repolarization induced by the procedure. No effects on either arrhythmias, or ECG patterns of ischemia were noted. We conclude that pharmacological inhibition of 5-lipoxygenase, shortly before percutaneous coronary intervention, reveals specific actions of leukotrienes on the heart rhythm. Inhibitors of 5-lipoxygenase might be of interest as a novel class of cardiac drugs affecting the conductive system.

4

Functional eicosanoid test and typing [FET] of peripheral blood cells in eicosanoid related diseases

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Schafer D. , Baenkler H. W.

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nr 5

103-118

EN

Monitoring of eicosanoid synthesis in peripheral blood cells has significant potential for improving the diagnosis and therapy of many human diseases. The quantitative relation between concentrations of prostaglandins and leukotrienes is central to the physiologic function of the eicosanoid network. Here we show that this regulation, which we call the functional eicosanoid typing (FET), fluctuates dynamically in individual living blood cells from patients, thereby limiting the accuracy with which concentration circuits of eicosanoids can transfer metabolic information. Using living cells in functional cell testing, we characterised the eicosanoid pattern score (EPS). A novel technique based on binomial errors on lipid mediator partitioning enabled calibration of in vivo biochemical parameters in molecular units. We found that eicosanoid production rates fluctuate over a time scale of about twenty minutes, while intrinsic noise decays rapidly. Thus, biochemical eicosanoid parameters, noise, and slowly varying cellular states together determine the effective FET. These results can form a basis for quantitative modelling of natural eicosanoid circuits in diagnosis of eicosanoid related diseases and design of synthetic ones for the prediction other diseases.

5

The role of leukotrienes in the pathogenesis of systemic sclerosis

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Chwiesko-Minarowska S. , Kowal K. , Bielecki M. , Kowal-Bielecka O.

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nr 2

6