38th Scientific
Meeting (GV - SOLAS)
Society for Laboratory Animal Science
(Essen, 2000)
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38th Scientific
Meeting (GV - SOLAS) |
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(Essen, 2000) |
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Lung Abstract 1 An alternative investigation method for animal experiments in ischemia/reperfusion injury. The use of pig lungs and blood from slaughterhouse for isolated organ perfusion v. v. Engelhardt A. (1), Dittrich S. (2), Lippek F. (3), Hegemann O. (2), Koios D. (2), v.d. Gröben J. (2), Grosse-Siestrup Ch. (1,4) and Lange, P. (2) Department of Animal Experiments (1), the Pathological Institute (3), Charité, Campus Virchow-Clinics and the Department of Congenital Heart Disease, Deutsches Herzzentrum (2), Berlin, Humboldt University of Berlin and Mediport Biotechnik Berlin (4). Introduction A large amount of pigs is raised for the production of meat. To replace the experiments with laboratory animals for medical research on organ transplantation, an alternative procedure could the use of organs from the slaughterhouse. But endemic or frequent disease could set limitations to this purpose. We investigate the influence of respiratory infections and stress related insufficient circulation on isolated organ perfusion with autologous blood. Method In our custom made examination criteria, organs and blood were taken from 6-7 months old "Deutsche Landrasse" (hybrid) pigs in commercial slaughterhouses. The condition of the living animals and their organ findings after slaughtery were divided into groups that revealed different health status. Result Compared to animals defined as healthy (n=6), haemodynamic and respiratory gas exchange is worse in lungs with pathologic findings (n=6) and in lungs of pigs with disregulated blood circuits (n=5). Conclusion Our simple diagnostic method is useful to guarantee a high quality of the pig lungs used for isolated organ perfusion. Abb. 1: Light microscopy of an healthy and an infected lung after 135 minutes extracorporal reperfusion with autologous blood  The pig lungs have been preserved in a intracellular solution (v. Baeyer II solution, Dittrich et al. 1998) Abb. 2: Light microscopy for circulatory classification after extracorporal reperfusion with autologous blood  Pictures of two lungs preserved with low potassium dextran LPD after 135 minutes reperfusion. In our pictures lungs are coloured with Haematoxilin-Eosin and have been zoomed with a factor of 100. The first slide preparation originates from lungs defined as healthy (Abb. 1.1, 2.1) whereas the second marks the situation defined as ill (Abb. 1.2, 2.2). Histological findings The slide preparations (Abb. 1.1, 2.1, 1.2, 2.2) do not only show an evident edema but also ruptures of the alveolar interstitial and the connective tissues aside from cell tumefactions, desquamation of the epithes, bleedings and haemostasis. In contrast to healthy reperfused lungs (Abb. 1.1 less inflammatory response) ill ones (Abb.1.2) show an enlargement of the peribronchial and the perivascular tissue with massive infiltration of leucocytes. If healthy lungs (Abb. 2.1) are compared, we can identify layers of homogene colour and structure with the reminds of hyaline membranes to lungs of circulatory disregulated pigs (Abb. 2.2 rectangulares). top Abstract 2 Assessment of the acute pulmonary toxicity of lamp oils (paraffin oil, Edenor ME 12 70, Edenor LPL) in perfused rat lungs S. Uhlig and R. Göggel Research Center Borstel, D-28845 Borstel Mainly among children incidental ingestion of conventional lamp oils (paraffin oil) is responsible for casual intoxications with frequently acute pulmonary toxicity and fatal consequences. On the basis of the isolated perfused rat lung we therefore developed a model to study the acute toxic effects of lamp oils. Isolated blood-free perfused and ventilated lungs were instilled with conventional lamp oil, the methyl ester Edenor® ME 12 70 or another ester Edenor® LPL and the changes in lung mechanics (pulmonary compliance and conductance) as well as the formation of edema (increase in lung weight) were studied. We observed that instillation of as little as 10 µl or 25 µl paraffin oil caused complete failure of lung functions within 20 min and even 2 µl caused noticeable edema. Similar results were obtained with Edenor® ME 12 70. In contrast, instillation of 2 µl Edenor® LPL had no effects on lung weight or lung functions, and instillation of 10 or 25 µl produced less dramatic results than observed with the two other oils at this dose. Compared to controls, at a dose of 10 µl pulmonary compliance and conductance were almost unaltered after instillation of Edenor® LPL, but were markedly decreased after instillation of the two other oils. Based on the increase in lung weight we estimated that Edenor LPL® is a five-fold less toxic to rat lungs than are conventional paraffin oil or Edenor® ME 12 70. Thus, if we assume a weight of children of 20 kg, we can extrapolate that after incidental intake 180 µl of paraffin oil in the lungs will most likely be toxic. In contrast, based on this extrapolation 180 µl of Edenor® LPL in the lungs will cause no lung damage, and even doses of 1 ml will probably be tolerated. top Abstract 3 In vitro studies on airway hyperreactivity in mice using isolated perfused lungs and precision-cut lung slices H.-D. Held, A. Wohlsen, Ch. Martin and S. Uhlig Division Pulmonary Pharmacology, Research Center Borstel, D-28845 Borstel Airway hyperreactivity (AHR) is a characteristic problem in patients suffering from asthma or byssinosis. Recently we have developed models that allow to study airway hyperresponsiveness in mice in vitro. Perfusion of isolated mouse lungs with bacterial endotoxins (>10 ng/ml), which may contribute to both asthma and byssinosis, increased AHR to methacholine. The endotoxin-induced AHR was prevented by a thromboxane receptor antagonist (SQ 29548). In line with this, the TP-receptor agonist U46619 induced AHR in both in perfused mouse lungs and in murine precision-cut lung slices. However, in perfused mouse lungs the LPS-induced AHR was unaffected by blockade of cyclooxygenases by non-selective (indomethacin, acetyl salicylic acid) or selective cyclooxygenase-2 (NS-398) inhibitors, but was attenuated by pretreatment with the antioxidant N-acetyl-cysteine. These findings suggested that the TP-receptor agonists responsible for the LPS-induced AHR might be metabolites formed by oxidative metabolism of arachidonic acid such as isoprostanes. And indeed we observed, that perfusion of mouse lungs with isoprostanes resulted in TP-receptor dependent AHR. In a separate set of experiments mice precision-cut lung slices (PCLS) were prepared from mice sensitised (for 2 weeks) and challenged with ovalbumin. Compared to controls, airways in these slices were hyperresponsive to methacholine. In contrast, passive sensitisation of rat or murine slices by overnight incubation with serum from sensitised animals did not result in AHR. However, at least with rat PCLS we observed that passively sensitised rat PCLS showed a typical early phase asthmatic response in that they immediately contracted in response to the antigen (ovalbumin). These findings show that both airway hyperreactivity and early asthmatic responses can be studied in perfused mouse lungs and precision-cut lung slices. Using these models we demonstrated that the LPS-induced airway hyperreactivity is mediated by cyclooxygenase-independent TP-receptor agonists, presumably by isoprostanes. top |
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| August 6, 2000 | Copyright
© 2000 (UNI - Klinikum |
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