Blood oxygen level–dependent measurement of acute intra-renal ischemia

Juillard, Laurent; Lerman, Lilach O.; Kruger, David G.; Haas, J. A.; Rucker, Brian C.; Polzin, Jason A.; Riederer, Stephen J.; Romero, J. Carlos

doi:10.1111/j.1523-1755.2004.00469.x

Cited by 136 publications

(109 citation statements)

References 27 publications

Supporting

Mentioning

104

Contrasting

Unclassified

Order By: Relevance

“…Renal oxygen consumption, V r O 2 ) (ml ⅐ min Ϫ1 ⅐ 100 g Ϫ1 ), was calculated as the product of RBF and the arterial-venous difference in O 2 content and normalized for renal weight (7,8). The arterial oxygen content (C a) was calculated by Ca ϭ (1.31 ⅐ Hb ⅐ SaO 2 ) ϩ (0.003 ⅐ PaO 2 ), and the renal venous content (C v) was calculated as Cv ϭ (1.31 ⅐ Hb ⅐ S rvO2)ϩ(0.003 ⅐ PrvO2), where Hb is hemoglobin concentration (mg/dl), SO 2 is O2 saturation (%) as determined by blood gas analysis in the artery ( a) or vein (rv), and PO2 is the arterial (a) or renal vein ( rv) oxygen tension (mmHg).…”

Section: Methodsmentioning

confidence: 99%

“…Nevertheless, prior work in our laboratory (7) suggests that renal tissue oxygenation (P t O 2 ) may be impaired during acute renal arterial stenosis. Therefore, the present study was designed to test the hypothesis that despite proportional changes in whole kidney O 2 delivery and consumption, acute progressive renal arterial stenosis (RAS) leads to decreases in regional renal tissue oxygenation.…”

mentioning

confidence: 90%

See 1 more Smart Citation

Regional decreases in renal oxygenation during graded acute renal arterial stenosis: a case for renal ischemia

Warner

Gomez

Bolterman

et al. 2009

American Journal of Physiology-Regulatory, Integrative and Comp

Self Cite

View full text Add to dashboard Cite

. Regional decreases in renal oxygenation during graded acute renal arterial stenosis: a case for renal ischemia. Am J Physiol Regul Integr Comp Physiol 296: R67-R71, 2009. First published October 29, 2008 doi:10.1152/ajpregu.90677.2008.-Ischemic nephropathy describes progressive renal failure, defined by significantly reduced glomerular filtration rate, and may be due to renal artery stenosis (RAS), a narrowing of the renal artery. It is unclear whether ischemia is present during RAS since a decrease in renal blood flow (RBF), O 2 delivery, and O2 consumption occurs. The present study tests the hypothesis that despite proportional changes in whole kidney O 2 delivery and consumption, acute progressive RAS leads to decreases in regional renal tissue O 2. Unilateral acute RAS was induced in eight pigs with an extravascular cuff. RBF was measured with an ultrasound flow probe. Cortical and medullary tissue oxygen ͑P t O 2 ͒ of the stenotic kidney was measured continuously with sensors during baseline, three sequentially graded decreases in RBF, and recovery. O 2 consumption decreased proportionally to O2 delivery during the graded stenosis (19 Ϯ 10.8, 48.2 Ϯ 9.1, 58.9 Ϯ 4.7 vs. 15.1 Ϯ 5, 35.4 Ϯ 3.5, 57 Ϯ 2.3%, respectively) while arterial venous O 2 differences were unchanged. Acute RAS produced a sharp reduction in O 2 efficiency for sodium reabsorption (P Ͻ 0.01). Cortical ͑P t O 2 ͒ decreases are exceeded by medullary decreases during stenosis (34.8 Ϯ 1.3%). Decreases in tissue oxygenation, more pronounced in the medulla than the cortex, occur despite proportional reductions in O 2 delivery and consumption. This demonstrates for the first time that hypoxia is present in the early stages of RAS and suggests a role for hypoxia in the pathophysiology of this disease. Furthermore, the notion that arteriovenous shunting and increased stoichiometric energy requirements are potential contributors toward ensuing hypoxia with graded and progressive acute RAS cannot be excluded.ischemia; renal tissue oxygenation; renal blood flow; pig THE TERM "ISCHEMIC NEPHROPATHY" has been used to describe progressive renal failure, defined by a significantly reduced glomerular filtration rate (GFR) or loss of renal parenchyma due to renal artery stenosis, a narrowing of one or more of the renal arteries. Ischemia, however, results from a rate of blood flow that is insufficient to satisfy metabolic demands, thereby leading to tissue hypoxia. There is little evidence to suggest that ischemic nephropathy is accompanied by renal tissue hypoxia (24). In fact, the kidney has a high blood flow relative to its weight (3), which results in very small arterial-venous differences in oxygenation, suggesting a large O 2 supply and limited O 2 consumption. Importantly, Nielsen et al. (15) found in patients with significant unilateral renal artery stenosis that O 2 consumption decreased with limited blood flow, suggesting that a decrease in O 2 supply is not enough to cause ischemic renal disease (22). Moreover, the reduced O 2 supply and demand s...

show abstract

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 90%

Regional decreases in renal oxygenation during graded acute renal arterial stenosis: a case for renal ischemia

Warner

Gomez

Bolterman

et al. 2009

American Journal of Physiology-Regulatory, Integrative and Comp

Self Cite

View full text Add to dashboard Cite

show abstract

“…In a model of acute renal arterial occlusion, BOLD revealed that increases in R 2 * paralleled the level of occlusion and reduction of renal blood flow (32). Indeed, patient with significant (33), but not moderate (34), renal artery stenosis show decreased renal oxygenation compared with essential hypertension.…”

Section: Blood Oxygen Level-dependent Mrimentioning

confidence: 96%

Renal Relevant Radiology

Ebrahimi

Textor

Lerman

2014

Clinical Journal of the American Society of Nephrology

Self Cite

View full text Add to dashboard Cite

SummaryBecause of its noninvasive nature and provision of quantitative measures of a wide variety of physiologic parameters, functional magnetic resonance imaging (MRI) shows great potential for research and clinical applications. Over the past decade, application of functional MRI extended beyond detection of cerebral activity, and techniques for abdominal functional MRI evolved. Assessment of renal perfusion, glomerular filtration, interstitial diffusion, and parenchymal oxygenation turned this modality into an essential research and potentially diagnostic tool. Variations in many renal physiologic markers can be detected using functional MRI before morphologic changes become evident in anatomic magnetic resonance images. Moreover, the framework of functional MRI opened a window of opportunity to develop novel pathophysiologic markers. This article reviews applications of some well validated functional MRI techniques, including perfusion, diffusion-weighted imaging, and blood oxygen level-dependent MRI, as well as some emerging new techniques such as magnetic resonance elastography, which might evolve into clinically useful tools.

show abstract

“…Blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) has been shown to be very useful in monitoring intrarenal oxygenation. [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32] A major advantage of the noninvasive BOLD MRI is the ability to perform similar measurement in humans.…”

mentioning

confidence: 99%

Early Changes With Diabetes in Renal Medullary Hemodynamics as Evaluated by Fiberoptic Probes and BOLD Magnetic Resonance Imaging

Santos

et al. 2007

Investigative Radiology

114

110

View full text Add to dashboard Cite

Objective-We sought to evaluate the influence of streptozotocin (STZ)-induced diabetes on renal outer medullary pO 2 and blood flow by invasive microprobes and to demonstrate feasibility that blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) can monitor these changes.Materials and 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-BothOxyLite 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.

show abstract

Blood oxygen level–dependent measurement of acute intra-renal ischemia

Cited by 136 publications

References 27 publications

Regional decreases in renal oxygenation during graded acute renal arterial stenosis: a case for renal ischemia

Regional decreases in renal oxygenation during graded acute renal arterial stenosis: a case for renal ischemia

Renal Relevant Radiology

Early Changes With Diabetes in Renal Medullary Hemodynamics as Evaluated by Fiberoptic Probes and BOLD Magnetic Resonance Imaging

Contact Info

Product

Resources

About