Reduced Oxygenation In Diabetic Rat Kidneys Measured By T2* Weighted Magnetic Resonance Micro-Imaging

  • Jenny Edlund
  • Peter Hansell
  • Angelica Fasching
  • Per Liss
  • Jan Weis
  • Jerry D. Glickson
  • Fredrik Palm
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 645)

Abstract

By applying invasive techniques for direct measurements of oxygen tension, we have reported decreased kidney oxygenation in experimental diabetes in rats. However, the non-invasive MRI technique utilizing the BOLD effect provides several advantages with the possibility to perform repetitive measurements in the same animals and in human subjects. In this study, we applied a modified single gradient echo microimaging sequence to detect the BOLD effect in kidneys of diabetic rats and compared the results to normoglycemic controls. All measurements were performed on inactin-anaesthetized adult male Wistar Furth rats. Diabetes was induced by streptozotocin (45 mg/kg) 14 days prior to MRI-analysis. Sixteen T2*-weighted image records (B0=1.5 T) were performed using radiofrequency spoiled gradient echo sequence with 2.6 ms step increments of TE (TE1=12 ms), while TR (75 ms) and bandwidth per pixel (71.4 Hz) were kept constant. T2* maps were computed by mono-exponential fitting of the pixel intensities. Relaxation rates R2* (1/T2*) in cortex and outer stripe of the outer medulla were similar in both groups (cortex for controls 22.3±0.4 vs. diabetics 23.1±1.8 Hz and outer stripe of outer medulla for controls 24.9±0.4 vs. diabetics 26.4±1.8 Hz; n=4 in both groups), whereas R2* was increased in the inner stripe of the outer medulla in diabetic rats (diabetics 26.1±2.4 vs. controls 18.8±1.4 Hz; n=4, P<0.05). This study demonstrates that experimental diabetes in rats induces decreased oxygenation of the renal outer medulla. Furthermore, the proposed T2*-weighted MR micro-imaging technique is suitable for detection of regional changes in kidney oxygenation in experimental animal models.

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Copyright information

© Springer Science+Business Media, LLC 2009

Authors and Affiliations

  • Jenny Edlund
    • 1
  • Peter Hansell
    • 1
  • Angelica Fasching
    • 1
  • Per Liss
    • 2
  • Jan Weis
    • 2
  • Jerry D. Glickson
    • 3
  • Fredrik Palm
    • 1
    • 4
  1. 1.Department of Medical Cell Biology,BMCUppsala UniversitySweden
  2. 2.Department of Oncology, Radiology and Clinical ImmunologyUniversity HospitalSweden
  3. 3.Department of RadiologyUniversity of PennsylvaniaPhiladelphiaUSA
  4. 4.Department of MedicineGeorgetown UniversityWashingtonUSA

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