title: Early changes with diabetes in renal medullary hemodynamics as evaluated by fiberoptic probes and BOLD magnetic resonance imaging.
abstract: OBJECTIVE
  We sought to evaluate the influence of streptozotocin (STZ)-induced diabetes on renal outer medullary pO2 and blood flow by invasive microprobes and to demonstrate feasibility that blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) can monitor these changes.
  
  
  METHODS
  A total of 60 Wistar-Furth rats were used. Diabetes was induced by STZ in 48. Animals were divided into OxyLite group (n=30) and BOLD MRI groups (n=30) each with a 5 subgroups of 6 animals: control and 2, 5, 14, and 28 days after induction of diabetes. Outer renal medullary oxygen tension and blood flow were measured by the combined OxyLite/OxyFlo probes.
  
  
  RESULTS
  Both OxyLite and BOLD MRI showed a significant increase in the renal hypoxia levels after STZ at all time points. However, no changes were observed in the outer renal medullary oxygen tension and blood flow between diabetic and control groups.
  
  
  CONCLUSIONS
  These preliminary results suggest that hypoxic changes can be detected as early as 2 days in rat kidneys with diabetes by BOLD MRI and that these early changes are not dependent on blood flow.
authors.affiliation: Center for Advanced Imaging, Department of Radiology, Evanston Northwestern Healthcare, Evanston, IL 60201, USA.
authors.forename: Elisabete Alcantara
authors.initials: EA
authors.lastname: dos Santos
authors.forename: Lu-Ping
authors.initials: LP
authors.lastname: Li
authors.forename: Lin
authors.initials: L
authors.lastname: Ji
authors.forename: Pottumarthi Vara
authors.initials: PV
authors.lastname: Prasad
mesh_terms: D000818:Animals; D003928:Diabetic Nephropathies / Q000175:diagnosis*; D005336:Fiber Optic Technology; D007679:Kidney Medulla / Q000098:blood supply*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods; D010101:Oxygen Consumption; D051381:Rats; D017208:Rats, Wistar; D012079:Renal Circulation / Q000502:physiology*; D013311:Streptozocin; D013997:Time Factors
chemical_list: D013311:Streptozocin