Critical considerations in teh development of an assay for sulfidopeptide leukotrienes in plasma

Heavey, Dennis J.; Soberman, Roy J.; Lewis, Robert A.; Spur, Bernd W.; Austen, K. Frank

doi:10.1016/0090-6980(87)90035-9

Cited by 54 publications

(16 citation statements)

References 23 publications

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“…LTB4 was then eluted with 2 ml methanol into polypropylene tubes. Since the spontaneous nonenzymatic conversion of LTC4 and LTD4 into LTE4 cannot be totally excluded, this process was initiated under controlled conditions prior to solid-phase extraction according to the method described by Heavey et al (1987). The Amprep PH columns were washed with 2 ml deionized water, 2 ml methanol (25%), and 2 ml hexane.…”

Section: Methodsmentioning

confidence: 99%

Investigations into the production and function of leukotrienes during histotropic development of Oesophagostomum dentatum

Daugschies

1996

Parasitol Res

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The dynamics of production and excretion of leukotrienes by parasitic larvae of Oesophagostomum dentatum and their role for the development of the larvae were studied. Larvae were cultured in vitro to the fourth stage (L4). Leukotriene B4 (LTB4) was detected in homogenates and in supernatant of larvae, with the homogenate-protein-based values steadily decreasing during development. The homogenate-protein-based values of peptidyl leukotrienes (pepLT) remained fairly stable in both homogenates and supernatants, whereas the wormcount-based pepLT values increased significantly. The addition of diethylcarbamazine (DEC) to the culture medium straight from the beginning of culturing (12.8 or 25.5 mmol/l) reversibly hampered growth and development to L4. Application of DEC at 12.8 mmol/l beginning on day 13 of in vitro cultivation exerted no significant effect on further development to L4. LTB4 appeared to counteract the inhibition of development by DEC. The results of this study indicate that endogenous LTs participate in regulation of the growth and development of O. dentatum.

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Section: Methodsmentioning

confidence: 99%

Investigations into the production and function of leukotrienes during histotropic development of Oesophagostomum dentatum

Daugschies

1996

Parasitol Res

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“…This contaminating immunoreactivity can be reduced by washes with petroleum ether and chloroform during Sep-Pak purification, suggesting that it derives from neutral lipids (Heavey et al, 1987 cross-reactivity with eicosanoids of low biological activity, and with those isomers of LTB4 generated non-enzymatically. The availability of a sensitive antiserum for LTE4 allowed the quantitation of this LT as a marker for total cysteinyl-LT production; our results demonstrate that over 90% of total cysteinyl-LT levels in sputum consisted of LTE4, which has lower activity on guinea-pig ileal smooth muscle preparations than LTC4 and LTD4 (Piper et al, 1981) and would therefore be under-estimated by bioassay techniques.…”

Section: Discussionmentioning

confidence: 99%

Leukotrienes in the sputum and urine of cystic fibrosis children.

Sampson

Spencer

Green

et al. 1990

Brit J Clinical Pharma

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1 Leukotrienes (LTs) are potent pro-inflammatory mediators with actions relevant to the pathophysiology of cystic fibrosis (CF), including increased mucus production, bronchoconstriction, leucocyte chemotaxis, and increased vascular permeability. We have therefore investigated the potential role of LTs in children with CF. Leukotriene E4 levels were assessed in the urine of 30 normal (N) children (aged 1.3-12.7 years) and 30 CF children (1.6-14.3 years). Sputum from 13 of the CF children was analysed from LTB4, LTC4, LTD4, and LTE4. LTs were separated by reversed-phase h.p.l.c. and quantitated by radioimmunoassay. 2 Urinary LTE4 levels were log normally distributed, with geometric mean values (95% confidence intervals) of N: 88.4 (71.3-111) pmol mmol-1 creatinine (n = 30), and CF: 112 (70.6-177) pmol mmol-1 creatinine (n = 30; P > 0.05). Of the CF subjects, 33% had urinary LTE4 levels above 200 pmol mmol-1 creatinine, compared with 3.3% of the N children.3 In sputum, mean (± s.e. mean) LT concentrations were (pmol g-1), LTB4: 44.3 ± 10.8, LTC4: 4.9 ± 1.3, LTD4: 1.8 ± 0.9, and LTE4: 67.7 ± 18.9 (n = 13). 4 Urinary LTE4 levels correlated significantly with sputum LTE4 levels (r = 0.673, P = 0.012), and with sputum levels of total cysteinyl-LTs (r = 0.660, P = 0.014). 5 In conclusion, total cysteinyl-LT content in sputum is 10-fold higher than previously reported, consisting primarily (91%) of LTE4. The high levels of LTE4 and LTB4 in sputum suggest involvement of LTs in the pathophysiology of CF. Urinary LTE4 levels may prove useful as a marker for cysteinyl-LT production in sputum.

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“…Urinary excretion of LTE4 has often been used as a marker of production of cysteinylleukotrienes in the lung [15][16][17][18][19][20][21]. In comparison with bronchial [14] or nasal lavages [13] or even blood sampling [26], collection of urine is a simple non-invasive, and safe method to obtain samples for analysis of leukotrienes. In the case of serum or plasma measurements, there is also a significant risk of artifactual formation of metabolites during sample collection, as previously shown for other arachidonic acid metabolites [cf.…”

Section: Introductionmentioning

confidence: 99%

Validation and application of a new simple strategy for measurements of urinary leukotriene E₄ in humans

Kumlin

Stensvad

Larsson

et al. 1995

Clin Experimental Allergy

108

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To monitor endogenous production of cysteinyl-containing leukotrienes, the end-metabolite leukotriene E4 (LTE4) was analysed in urine. Results obtained with a sensitive enzyme immunoassay (EIA), performed on crude urine samples correlated well with data obtained from a previously reported radioimmunoassay. Enzyme immunoassay analysis of unextracted urine was justified by an excellent agreement between analyses in crude samples and measurements achieved after purification on solid phase extraction followed by separation on reversed-phase high performance liquid chromatography. Moreover, LTE4 was stable in urine samples stored at -20 degrees C, for months without the addition of preservatives. The stability of LTE4 in urine was not improved by addition of the antioxidant 4-hydroxy-TEMPO and pH adjustment to 9. As assessed by EIA analysis in crude urine samples, baseline values for urinary leukotriene E4 were not significantly different between atopic asthmatic subjects and non-asthmatic individuals, and there was no diurnal variation in urinary excretion of LTE4 in healthy subjects. However, we confirmed earlier data on significantly higher basal levels of urinary LTE4 in aspirin-intolerant asthmatics. In addition, a post-challenge increase in urinary LTE4 levels was detected in association with allergen-induced airway obstruction in atopic asthmatics. The per cent increase in urinary LTE4 was similar, irrespective of whether the samples were purified or not prior to EIA. Thus, combined with random validation by high performance liquid chromatography, the strategy of direct EIA of serially diluted urine samples was found to be a good index of in vivo production of leukotrienes. This was further reinforced by the demonstration that pretreatment with the leukotriene biosynthesis inhibitor Bay x 1005 inhibited the post allergen-challenge increase in urinary LTE4, as shown both with unpurified and purified samples.

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Critical considerations in teh development of an assay for sulfidopeptide leukotrienes in plasma

Cited by 54 publications

References 23 publications

Investigations into the production and function of leukotrienes during histotropic development of Oesophagostomum dentatum

Investigations into the production and function of leukotrienes during histotropic development of Oesophagostomum dentatum

Leukotrienes in the sputum and urine of cystic fibrosis children.

Validation and application of a new simple strategy for measurements of urinary leukotriene E₄ in humans

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Critical considerations in teh development of an assay for sulfidopeptide leukotrienes in plasma

Cited by 54 publications

References 23 publications

Investigations into the production and function of leukotrienes during histotropic development of Oesophagostomum dentatum

Investigations into the production and function of leukotrienes during histotropic development of Oesophagostomum dentatum

Leukotrienes in the sputum and urine of cystic fibrosis children.

Validation and application of a new simple strategy for measurements of urinary leukotriene E4 in humans

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Validation and application of a new simple strategy for measurements of urinary leukotriene E₄ in humans