title: 31P NMR spectroscopy of photodynamically treated cells.
abstract: The metabolic response of Chinese Hamster Ovary (CHO) cells during photodynamic therapy (PDT) with hematoporphyrin IX (Hp IX) and pheophorbide (Ph) was monitored in real time by 31-phosphorous (31P) nuclear magnetic resonance (NMR) spectroscopy. The effects of the delivered light dose and of cell oxygenation were investigated. A delayed disappearance of nucleoside triphosphate (NTP) following irradiation was observed, which was related to the treatment efficiency. For cells irradiated with a light dose of 0.8 J/cm2 in the presence of Hp IX, the disappearance of the NTP peaks occurred within 30 minutes of irradiation, but for an irradiation of 0.24 J/cm2, the disappearance of the NTP peaks occurred about 6 hours later, and this delayed disappearance is related to the surviving fraction. For irradiation experiments involving Ph and a light dose of 0.036 J/cm2, NTP in injured cells began to decrease about 3 hours after irradiation, whereas for a light dose of 0.24 J/cm2, we observed the instantaneous disappearance of the NTP peaks occurring during the irradiation time. The same efficiency was obtained with two different oxygen partial pressures in the perfusate (360 and 154 mmHg) and a light dose of 0.24 J/cm2.
authors.affiliation: Institut de Physique Biologique, URA CNRS 1173, Faculté de Médecine, Université Louis Pasteur, Strasbourg, France.
authors.forename: T
authors.initials: T
authors.lastname: Schunck
authors.forename: P
authors.initials: P
authors.lastname: Poulet
authors.forename: J
authors.initials: J
authors.lastname: Steibel
mesh_terms: D000818:Animals; D016466:CHO Cells; D002470:Cell Survival; D006224:Cricetinae; D004734:Energy Metabolism; D017324:Hematoporphyrin Derivative / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D009711:Nucleotides / Q000737:chemistry; D010101:Oxygen Consumption; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000737:chemistry*
chemical_list: D009711:Nucleotides; D017319:Photosensitizing Agents; D017324:Hematoporphyrin Derivative