RESUMEN
A novel nuclear magnetic resonance (NMR) spectroscopy probe was designed and constructed for the study of transient metabolic changes in cellular systems during exposure to ionizing radiation. The probe incorporated a bioreactor, a radiation source, and a radiofrequency detection circuit tunable between 100 and 300 MHz for in vivo NMR spectroscopy of 23Na, 13C, and 31P at 11.7 Tesla. The bioreactor system allowed perfusion, oxygenation, and temperature control of cultured cells during irradiation and while performing simultaneous spectroscopic experiments. The concentric design of the bioreactor allowed for the insertion of a 192Ir gamma ray source (E(gamma) = 370 keV) to allow irradiation of the bioreactor system during the acquisition of NMR spectra. Initial results of 31P spectra obtained during simultaneous gamma irradiation of Saccharomyces cerevisiae at approximately 8 Gy/hr show rapid decreases in adenosine triphosphate (ATP) and polyphosphate at the onset of irradiation followed by a slow recovery of polyphosphate.