Researchers report that giving a combination of the amino acids L-Arginine and N-Acetylcysteine (NAC) to men with high blood pressure and diabetes improved endothelial function, Endothelial dysfunction frequently occurs in these patients. It is a condition where the lining of the arteries becomes unable to respond to increases in blood flow--a process that initiates atherosclerosis. The researchers enrolled 24 men between the ages of 51 and 74 who were being treated for type 2 diabetes and high blood pressure.