Chemiluminescence of bronchoalveolar lavage cells as an indicator of leukocyte activation in rats with a hyperreactive bronchus

Background: The Lewis rat among highly inbred strains exhibits significant airway hyperresponsiveness (AHR) following intravenous administration of Sephadex G-200 (Sephadex). The aim of this study was to investigate the association of Sephadex-induced AHR with changes in airway inflammation in Lewis rats. Methods: A suspension (0.5 mg/ml/rat) of Sephadex was intravenously administered to male Lewis rats on days 0, 2 and 5. Measurement of airway responsiveness to serotonin, bronchoalveolar lavage (BAL) and histological study were performed on day 2–11. Results: Significant AHR induced by Sephadex was recognized on day 2 (p < 0.05), and AHR reached a maximum on day 7 (p < 0.001). In the BAL study, eosinophils increased on day 2 (p < 0.01) with a peak on day 5 (p < 0.05). In the histological study, we found Sephadex beads trapped in small arteries of the lung and granulomatous arteritis on day 2 or later. Pulmonary granulomas, horseshoe-shaped multinuclear giant cells, eosinophils and goblet cell hyperplasia were observed on day 2, and the degree became intense on day 5–7. GCC-AP0341 (10 mg/kg, i.p. × 3) inhibited the recruitment of eosinophils in BAL fluid and in lung tissue, but it did not inhibit AHR. The compound also inhibited pulmonary granulomas and goblet cell hyperplasia. Conclusion: The mechanism of Sephadex-induced AHR may not be directly associated with inflammatory changes such as recruitment of eosinophils, pulmonary granulomas and hyperplasia of goblet cells in rats.

Section: Discussionmentioning

confidence: 99%

Inhibition of Pulmonary Eosinophilia Does Not Necessarily Prevent the Airway Hyperresponsiveness Induced by Sephadex Beads

Matsubara

Fushimi

Ogawa

et al. 1998

“…Details of the methods have already been reported by us else where [14,19]. The most important technical details are summarised below.…”

Section: Introductionmentioning

confidence: 99%

“…In addition, there were increased numbers of eosinophils in the air ways accompanied by hyperreactivity to i.v. 5-hydroxytryptamine [12,13] and aerosols of 5-hydroxytryptamine and ovalbumin in sensitised animals [14], Despite embol isation of the pulmonary vessels, it was not possible to re produce this effect by i.v. injection of latex particles [15], which points to a Sephadex-specific effect for the eosinophilia, possibly as a result of the known endogenous dextran hypersensitivity of rats [16], Inbred Brown-Norway rats appear to be a suitable rat strain for an animal model in asthma, since this strain is characterised by a high immunoglobulin E response to sensitisation to antigen and by blood cosinophilia [17,18].…”

mentioning

confidence: 99%

Intratracheal Application of Sephadex in Rats Leads to Massive Pulmonary Eosinophilia without Bronchial Hyperreactivity to Acetylcholine

Kubin¹,

Deschl²,

Linssen³

et al. 1992

Fourteen Brown-Norway rats were pretreated with physiological saline (n = 7) or 500 μg Sephadex (n = 7) intratracheally. 24 h later, a bronchial provocation test was performed under pentobarbital anaesthesia using increasing doses of acetylcholine aerosol and the degree of bronchospasm was measured using a modified Konzett-Rössler method. Subsequently, leucocyte counts were determined in the bronchoalveolar lavage fluid (BALF), BALF cells were differentiated, and the chemiluminescence of the BALF leucocytes were measured. Finally, the lungs were removed and histologically examined. The cell count in the BALF was significantly (p < 0.05) increased in the animals pretreated with Sephadex compared to those in the saline group (mean value ± SEM: 0.38 ± 0.07 vs. 0.15 ± 0.02 × 10⁶/ml). This difference was also reflected in the chemiluminescence measurements (2.51 ± 0.53 vs. 0.20 ± 0.03 × 10⁶ counts/0.5 ml). In the Sephadex-treated animals there was also a significant increase in the absolute number of neutrophil (0.040 ± 0.010 vs. 0.011 ± 0.002 × 10⁶/ml) and, in particular, eosinophil granulocytes (0.188 ± 0.055 vs. 0.003 ± 0.001 × 10⁶/ml) in the total leucocytes of the BALF. Lung histology showed massive perialveolar and peribronchial oedema and granulomatous infiltrates, primarily with eosinophils, after intratracheal application of Sephadex; these findings were not observed in the saline group. None of these changes in the rats pretreated with Sephadex manifested themselves in increased bronchial reactivity to acetylcholine aerosol. It is uncertain if the Sephadex-induced increase in the eosinophil count is accompanied by an activation of this cell population, which appears to be of importance for the occurrence of bronchial hyperreactivity. It is clear from this animal model that the presence of inflammatory cells in the BALF and lung tissue of rats does not in itself result in increased reactivity of the airways.

“…Pooled BALF was centrifuged (800 g. 15 min) to separate the cells. The cells were resuspended and counted, using a Coulter Counter ZB, (Coulter, Krefeld, FRG) and luminol-amplified chemiluminescence (CL) of lavage cells was measured follow ing stimulation with opsonized zymosan as described previously [9]. Cell-free BALF was analyzed either directly after the lavage, or after storage at -2 0°C for up to 8 weeks (loss of enzyme activity during this period was negligible).…”

Section: Methodsmentioning

confidence: 99%

“…In part of the experi ments, bronchoconstrictions (BC) induced by aerosols of stepwise increasing dosages of 5-HT preceded BAL. The measurement of BC was performed according to Konzett and Roessler [9].…”

Section: Methodsmentioning

confidence: 99%

Late Phase Increase of Thrombin-Like Proteinase, Protein, Leukocytes in Bronchoalveolar Lavage (BAL) Fluid and Chemiluminescence of BAL after Ovalbumin Aerosol Inhalation by Actively Immunized Rats

Linssen

Lemmermann²,

Lipponer³

et al. 1991

Self Cite

A thrombin-like proteinase (THROLP) was detected colorimetrically as the main proteolytic activity (PROA) in bronchoalveolar lavage fluid (BALF) 4 and 24 h after ovalbumin aerosol (OVA) challenge of actively immunized rats. Other proinflammatory parameters increased also significantly in BALF, like chemiluminescence of leukocytes (1 h), protein and cell number (24 h after challenge). In parallel, increased bronchoconstrictions against 5-HT aerosols are detected 24 h post OVA challenge. THROLP is an indicator for plasma leakage, activation of the clotting reaction and the protracted inflammation in the airways, which induced bronchial hyperreactivity.