Effect of Homocysteine on Bovine Aortic Endothelial Cell Function

Abstract

Hypothesis: In hyperhomocyst(e)inemic states, oxidative stress resulting from elevation of homocyste(e)ine levels leads to a decrease in L-arginine transport activity and a decrease in intracellular L-arginine availability. This will in turn limit NO production and increase superoxide production from eNOS. Therefore, the oxidative stress will be increased in endothelial cells, which may eventually lead to endothelial dysfunction and predispose to atherothrombosis. SPECIFIC AIMS 1. Characterize the cationic amino acid transport systems in bovine aortic endothelial cells (BAECs). 2. Examine the effect of HCY on L-arginine transport over time. 3. Determine the influence of oxidative stress, which is produced by HCY, on L-arginine transport. 4. Determine the effect of HCY on endothelial cell membrane potential. 5. Determine effect of HCY on expression of the transport protein CAT-1. 6. Determine the effect of HCY on eNOS activity, eNOS protein levels and NO formation. 7. Determine the effect of HCY on the production of 3-nitro-tyrosine, a marker for production of peroxynitrite. 8 . Determine the effect of HCY on vascular responses to acetylcholine.