Fig. 1.

Portions of 800-MHz ¹H NMR spectra obtained using 3-mm sample tubes highlighting the sensitivity of coenzyme levels to tissue harvesting/extraction protocols: (a) mouse heart harvested, washed with glucose/pyruvate solution, and freeze clamped, followed by extraction using methanol-chloroform mixture; (b) mouse heart harvested, perfused with glucose/pyruvate solution, and freeze clamped, followed by extraction using methanol-chloroform mixture; (c) mouse heart freeze clamped in vivo, followed by extraction using methanol-chloroform mixture; and (d) mouse heart harvested, washed with PBS, and freeze clamped, followed by extraction using methanol-water mixture. The most prominent changes are the missing NADH/NADPH peaks in (b) and diminished ATP and enhanced ADP/AMP in (b–d) (reproduced with permission from ref. 17)