Fachbereich Veterinärmedizin



    Die isoliert perfundierte Rattenaorta (2016)

    Siegel, Nathalie (WE 2)
    Berlin, 2016 — iii, 93, III Seiten
    URL (Volltext): http://www.diss.fu-berlin.de/diss/receive/FUDISS_thesis_000000102846
    Institut für Veterinär-Physiologie

    Oertzenweg 19 b
    14163 Berlin
    Tel.+49 30 838 62600 Fax.+49 30 838-62610

    Abstract / Zusammenfassung

    Medial vascular calcification, also known as arteriosclerosis, plays a vital role in the development of cardiovascular diseases. It frequently occurs in patients with chronic renal disease, where it is associated with increased morbidity and mortality. Contrary to former opinions, medial vascular calcification is an actively regulated process, influenced by various factors. A so far poorly studied factor is the role of the endothelium. For studying vascular calcification, there are several in vitro-, ex vivo- and in vivo-models available in which vascular calcification is induced by different methods. However, each of these models shows certain disadvantages. The goal of this thesis was the development and establishment of a novel physiological ex vivo-model: The Isolated Perfused Aorta (IPA). Rat aortas were placed in a perfusion chamber, integrated into a circular flow and perfused with cell culture medium for 14 days. Calcification was induced by substances added to the medium. It was found that the IPA imitates physiological conditions better than existing in vitro- and ex vivo-models and it burdens the animals less than in vivo-models. Due to its good accessibility it also allows to study the role of the endothelium in medial vascular calcification. The first step was the development and optimization of methods. A technique for the gentle isolation and preparation of aortas was developed, the composition of perfusion media was optimized and the experimental design was developed and optimized, as well as the experimental process. After the successful development of the model it was examined, whether calcification could be induced by perfusion with a calcifying medium. Therefore, experiments with calcifying medium and control medium were performed. 12 aortas from 4 calcifying experiments and 9 aortas from 3 control experiments were analyzed. The amount of calcium in the aortas was quantified by photometric measurement and examined histologically by stainings for calcium detection. The average amount of calcium in aortas from control experiments was 1.68 g/mg. In calcifying experiments it reached 4.42 g/mg. The difference was significant. Thus, it is possible to induce a medial calcification of the aortic wall in the model of the IPA. Histology supported this result. Moreover, it showed that the incorporated calcium was located in the media of the aortic wall. This corresponded with the processes in vivo, opposed to the ex vivo calcified controls, in which the calcium incorporations were located unselectively in all wall layers. With the IPA, a model for studying the medial vascular calcification was developed and established. It allows the specific manipulation and investigation of the endothelium and it simulates physiological conditions better than established in vitro- and ex vivo-models.