Document Details

Document Type:   Thesis
Title:   Enumeration of Endothelial Progenitor Cells in Hind Limb Suspended Rats and the Mechanics of Endothelial Wound Healing
Author:   Jarrod Matthew Pennington
College:   Science
Degree Program:   Biological Sciences, M.S.
Degree:   Master of Science
Committee Director:   Elmer Price
Document Availability:   Document available for World-Wide access.
Date of Defense:   08/26/2009

The endothelium repairs itself through two methods. One is by the activity of circulating endothelial progenitor cells (EPCs), immature cells capable of proliferation and differentiation that circulate the bloodstream. The other is through the migration of existing mature endothelial cells. It is thought that EPCs contribute to the repair and replacement of damaged endothelium. Physical inactivity and bed rest are known to be deleterious to the endothelium and may also be deleterious to EPC numbers, which would impair endothelial replacement. We used HLS rats as a model for physically inactive patients to examine its effects on circulating EPC populations and hypothesized that HLS rats will exhibit fewer EPCs than control rats. A rat blood mononuclear cell fraction was stained with fluorescent antibodies and observed via flow cytometry. We did not find any significant differences cell surface marker expression between control and HLS rats. To further understand the mechanics of in vivo healing, we subjected human umbilical vein endothelial cells (HUVECs) to drugs and observed their effects on in vitro healing. We hypothesized that wound healing migration is controlled by cytoskeletal elements. Wounded cells were photographed hourly and healing rate was measured. We observed that rate of healing slows over time, and disruption of cytoskeletal elements slows healing. We concluded that HLS is insufficient to alter EPC numbers. In addition, we conclude that the microtubule components of the cytoskeleton are critical to wound healing. 

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