Growth hormone deficiency (GHD) is associated with increased cardiovascular morbidity and mortality. The effects of such a deficiency include decreased exercise capacity and tolerance, impaired cardiac function, a central fat redistribution, increased peripheral arterial resistance, and an unfavorable lipid profile. These effects have been found to be reversed with appropriate replacement therapy with recombinant human growth hormone. We plan to utilize several experimental systems to further investigate the role of growth hormone (GH) in maintaining cardiovascular health. In particular, we would like to further understand the interaction of GH with Plasminogen-activator-inhibitor-1 (a major activator of the fibrinolytic system) as well as the role of GH in the maintenance of vascular function.