Figure 1. Average nuclear magnetic resonance (NMR) metabolite determinations versus time during nitric oxide synthase (NOS) inhibitor pretreatment and hypoxia studies. The x axis depicts the time in minutes since the beginning of the NMR experiment. Times of hypoxia and recovery (reperfusion with oxygenated artificial cerebrospinal fluid [ACSF]) are indicated on the figure. Data are shown as the mean +/- SD, from experiments with 27 [micro sign]M 7-nitroindozole (7-NI) pretreatment (open circles), 27 [micro sign]M L-nitroarginine methyl ester (L-NAME) pretreatment (solid circles), 27 [micro sign]M L-nitroarginine (L-NOarg) pretreatment (solid triangles), and without NOS inhibitor pretreatment (open triangles); n = 3 for each of these groups. (A)[Greek small letter beta]-Adenosine triphosphate quantitations, and (B) phosphocreatine (phosphocreatine) quantitations. The y axis indicates the integrated NMR signal intensity normalized to its own control value (at t = 0). (C) The intracellular pH was obtained from [Greek small letter delta], the P^{i-phosphocreatine}chemical shift, using the same formula as in our previous studies.