Pharmacokinetic Effect of AstraGin on Arginine Absorption and Nitric Oxide Production in Healthy Subjects

Before each study day, the participants were subjected to a reduced nitrate content diet (avoid foods such as dark chocolate, beets, garlic, nuts and seeds, bacon, ham, and hot dogs,, day-1) for 24h. All subjects took a 50 mg placebo (maltodextrin) capsule at 9 p.m. and began fasting for 12 hours, except for a small amount of water in the night before the experiment. On each study day, all subjects collected their first blood sample at 9 a.m. from the median cubital vein using the indwelling catheter method. After the first blood collection, all subjects took 50 mg placebo and 5 g of L-arginine with 250 mL water. Additional blood samples were collected at 0, 15, 30, 45, 60, 90, 120, 150, and 180 min for analysis of the plasma concentration of amino acids, total nitrite, nitrate, and asymmetric dimethylarginine (ADMA) content. All subjects collected their urine during 0 \~ 180 min to measure 1) nitrate and 2) cGMP content.