Oscillatory Flow Effects on Rat Aortic Smooth Muscle Cells

Diploma Thesis from the year 1997 in the subject Medicine - Biomedical Engineering, grade: 1,2, Clark Atlanta University (unbekannt), language: English, abstract: Inhaltsangabe:Abstract:§A cell culture System to mimic the circumferential expansion of the arterial wall was supplemented with a flow control System for model enhancement. The given System imposed uniaxial sinusoidal stretch (1 Hz) with a 10 % elongation to an elastic silicone substrate upon which rat aortic smooth muscle cells were cultured. Occurring fluid motion during a stretch experiment caused oscillating shear stress upon the Gell layer of approximately 0.6 dynes/cm2 (60 x 10-3 N/m2) and was controlled by the newly added oscillatory flow System.§Experiments were performed and investigated at 0, 4, and 24 hours. Morphological observations correlated with the results obtained by the initial stretch experiments. A final median angle of orientation of 60° - 70° from the axis of stretch was observed. Both control cultures remained randomly oriented throughout all experiments. Inhibition of cell proliferation alter 4 hours of cyclic stretch, observed by Karen J. Schnetzer could not be confirmed. However, growth related results did correspond to the preceding study in a qualitative manner. Influences of oscillatory flow an SMC growth and morphology were not different to the steady-stretch control. Analysis of results confirmed the assumption made for the earlier culture system, that effects of oscillatory fluid motion occurring during the cyclic stretch experiment could be neglected.§Inhaltsverzeichnis:Table of Contents:§AcknowledgmentsV§List of FiguresIX§List of TablesXI§List of SymbolsXIII§1.Introduction1§2.Background and Literature Review3§2.1Arterial Anatomy4§2.2Arterial Physiology6§2.3Arterial Mechanics7§2.3.1Tensile Stress and Arterial Wall Deformation7§2.3.2Shear Stress8§2.4Arterial Pathology10§2.4.1Atherosclerosis10§2.4.2Hypertension12§2.4.3Smooth Muscle Cells in Arterial Disease12§2.5Cell Culture Models of Arterial Mechanics13§2.5.1Shear Models14§2.5.2Stretch Models14§3.Materials and Methods17§3.1Stretch Chamber17§3.1.1Demands on the Stretch System18§3.1.2Stretch Chamber Design19§3.2Flow Chamber20§3.2.1Mathematical Description of the Flow22§3.2.2Demands on the Flow Chamber27§3.2.3Flow Chamber Design27§3.3Elastic Substrate31§3.3.1Silicone Membranes31§3.3.2Extracellular Matrix33§3.4Cell Culture35§3.4.1Smooth Muscle Cells36§3.4.2Culture. Procedures37§3.5Experimental Set-Up40§3.5.1Equipment Preparation40§3.5.2Substrate Preparation41§3.5.3Cell Seeding Method43§3.5.4Stretch and Flow Chamber Assembling44§3.5.5Experimental Performance45§3.5.6Microscopic Visualization and Documentation46§3.5.6.1Phase Contrast Microscopy46§3.5.6.2Fluorescent Microscopy46§3.5.6.3Video Imaging System46§3.6Experimental Data Analysis48§3.6.1Morphological Analysis48§3.6.2Cell Proliferation Analysis49§3.6.2.1Proliferating Cell Nuclear Antigen50§3.6.2.2Immunofluorescent Staining Techniques51§3.6.2.3Total Staining52§4.Results53§4.1Observation Methods and Conditions53§4.2Observation of Cell Morphology55§4.2.1Cell Shape55§4.2.2Cell Orientation57§4.2.3Cell Area59§4.3Observation of Cell Proliferation60§5.Discussion64§5.1Discussion of the Cell Culture System64§5.1.1Stretch Unit65§5.1.2Flow Unit65§5.2Discussion of the Experimental Results66§5.2.1Cell Morphology Data66§5.2.2Cell Growth Related Data68§6.Conclusions70§7AppendicesXV§7.1Appendix A: Summaries of Data and Statistical AnalysisXV§7.2Appendix B: Cell Pictures of Morphological ObservationsXXI§7.3Appendix C: Deta...