Fig. 2.
Advantages associated with the stability of the cell perfusion system. (A) Reproducibility of the pyruvate-to-lactate conversion process in perfused cells, as illustrated by the lactate's normalized signal intensity observed in two 4.8 mM 13C1-pyruvate injections 15 h apart. (B) Independent evidence of the system's stability, as revealed by 31P NMR spectra recorded on perfused T47D human breast cancer cells at various times between the injections of the hyperpolarized pyruvate. PME-phosphomonoesters, PCho-phosphocholine, PCr-phosphcreatine, NTP-nucleoside-triphosphate, UDPS-uridine diphosphosugar. (C) DNP-derived rate parameter k values vs. the γNTP/Pi ratio, for injections of a 9.75 mM hyperpolarized pyruvate solution on eight different batches of T47D cells.