There is significant evidence that HMG-CoA reductase inhibitors, a commonly used class of cholesterol lowering medications, reduce the risk of death from coronary disease. Although these medicines lower cholesterol levels, other studies suggest that they have an additional effect on improving blood vessel functioning. It has also been shown that consumption of a fatty meal temporarily alters blood vessel functioning, causing endothelial dysfunction. This study will examine if pravastatin, an HMG-CoA reductase inhibitor, improves blood vessel functioning after a fatty meal. We plan on enrolling 32 subjects, aged 18-40 years, who are healthy with no history of diabetes, smoking, high blood pressure, or heart disease. These subjects will be randomly assigned to initially receive four days of pravastatin or an inactive substance, and then crossed over to the other group. Blood vessel functioning will be monitored by a technique called flow mediated vasoactivity, which uses ultrasound measurement of the forearm artery and its response to temporary occlusion. This primary measure of flow mediated vasoactivity will be done before and after consumption of a fatty meal. We hope to show that treatment with pravastatin prevents the blood vessel dysfunction known to occur after a high fat meal. Secondary outcomes will include measurement of endothelin-l, a mediator of blood vessel functioning, and assessment of changes in lipid profiles. If pravastatin does prevent endothelial dysfunction in this setting, it could lead to further studies about their use in more acute medical settings, including heart attacks or strokes.