title: Absolute oxygen tension (pO(2)) in murine fatty and muscle tissue as determined by EPR.
abstract: The absolute partial pressure of oxygen (pO(2)) in the mammary gland pad and femoral muscle of female mice was measured using EPR oximetry at 700 MHz. A small quantity of lithium phthalocyanine (LiPc) crystals was implanted in both mammary and femoral muscle tissue of female C3H mice. Subsequent EPR measurements were carried out 1-30 days after implantation with or without control of core body temperature. The pO(2) values in the tissue became stable 2 weeks after implantation of LiPc crystals. The pO(2) level was found to be higher in the femoral muscle than in the mammary tissue. However, the pO(2) values showed a strong dependence on the core body temperature of the mice. The pO(2) values were responsive to carbogen (95% O(2), 5% CO(2)) breathing even 44-58 days after the implantation of LiPc. The LiPc linewidth was also sensitive to changes in the blood supply even 60 days after implantation of the crystals. This study further validates the use of LiPc crystals and EPR oximetry for long-term non-invasive assessment of pO(2) levels in tissues, underscores the importance of maintaining normal body core temperature during the measurements, and demonstrates that mammary tissue functions at a lower pO(2) level than muscle in female C3H mice.
authors.affiliation: Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892-1002, USA.
authors.forename: Atsuko
authors.initials: A
authors.lastname: Matsumoto
authors.forename: Shingo
authors.initials: S
authors.lastname: Matsumoto
authors.forename: Anastasia L
authors.initials: AL
authors.lastname: Sowers
authors.forename: Janusz W
authors.initials: JW
authors.lastname: Koscielniak
authors.forename: Nancy J
authors.initials: NJ
authors.lastname: Trigg
authors.forename: Periannan
authors.initials: P
authors.lastname: Kuppusamy
authors.forename: James B
authors.initials: JB
authors.lastname: Mitchell
authors.forename: Sankaran
authors.initials: S
authors.lastname: Subramanian
authors.forename: Murali C
authors.initials: MC
authors.lastname: Krishna
authors.forename: Ken-Ichiro
authors.initials: K
authors.lastname: Matsumoto
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism*; D000818:Animals; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D005260:Female; D007211:Indoles; D051379:Mice; D008809:Mice, Inbred C3H; D018482:Muscle, Skeletal / Q000378:metabolism*; D009942:Organometallic Compounds; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption / Q000502:physiology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013113:Spin Labels
chemical_list: D007211:Indoles; D009942:Organometallic Compounds; D013113:Spin Labels; C081756:lithium phthalocyanine; D010100:Oxygen