Figure 4: In Vitro Studies of Plasma Nitrite and Enzyme Activity

(A) Plasma nitrite rose significantly in normal individuals, but did not reach significance in those with the *2 variant (*p < 0.05, n = 8 vs. 7). Solid circles = ALDH2*1/*1; open circles = ALDH2*1/*2. (B) Sodium nitrite inhibited aldehyde dehydrogenase activity of ALDH2*1 (p < 0.01 compared with baseline), but not *2, though the resting level of activity was far lower (n = 3 for each). (C) The ALDH2*2 variant enzyme exhibits a rightward shift in the NO-generation curve in response to nitrite when compared with the wild-type enzyme (p < 0.05, n = 3). Solid line = ALDH2*1; dotted line = ALDH2*2. DTT = dithiothreitol; sGC = soluble guanylate cyclase.