Furthermore , the ratio between acetylcholine and nitroprusside , a marker of endothelial NO synthase activity , was significantly greater in the young volunteers ( 0.816 + / - 0.094 % vs. 0.892 + / - 0.146 % vs. 1.389 + / - 0.2 % , in atherosclerotic vascular disease , healthy elderly group , and young controls respectively ) .
