Early changes with diabetes in renal medullary hemodynamics as evaluated by fiberoptic probes and BOLD magnetic resonance imaging.
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.
dos Santos
Elisabete Alcantara
EA
Center for Advanced Imaging, Department of Radiology, Evanston Northwestern Healthcare, Evanston, IL 60201, USA.
Li
Lu-Ping
LP
Ji
Lin
L
Prasad
Pottumarthi Vara
PV
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
D013311:Streptozocin