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Renal Tissue Oxygenation with Renal Arterial Stenosis
Author(s) -
Warner Lizette,
Gomez Sabas,
Haas John A,
Bolterman Rodney,
Bentley Michael D,
Joyner Michael J,
Lerman Lilach O,
Romero Juan Carlos
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.969.6
Subject(s) - renal blood flow , medicine , oxygenation , reabsorption , renal artery stenosis , cardiology , kidney , chemistry , endocrinology , renal artery
Functional renal oxygen consumption, V r O 2 is due to tubular reabsorption of sodium (T Na ) in the proximal (∼67%) and distal(∼30%) nephrons, resulting in compartments (cortex/medulla) with distinct V r O 2 /T Na relationships. A progressive drop in renal blood flow (RBF) with renal arterial stenosis (RAS), disrupts O 2 delivery, vital for reabsorption. The overall objective for the study is to determine the intra‐renal regional alterations in tissue oxygenation (P t O 2 ) and theV r O 2 /T Na relationship in acute RAS. The hypothesis is RAS is accompanied by intra‐renal regional changes in oxygenation. Unilateral acute RAS was induced in 8 pigs by an extra‐vascular balloon. RBF and P t O 2 were measured continuously with an ultrasound flow probe during baseline, RBF autoregulation and 3 sequential decreases in RBF, recovery, and furosemide administration. V r O 2 was determined using Fick arterio‐venous differences. There were concomitant decreases in V r O 2 , and P t O 2 throughout the occlusion periods. Medullary P t O 2 changes were 35% more pronounced than cortical. This study suggests medullary decreases in P t O 2 are more aggravated than cortical changes with reductions in RBF, accentuating the medulla's vulnerability to progressive RAS. Mild to moderately severe obstructions seem to preserve the tubular transport costs. Funding provided by NIH Grant (HL16496‐32), 2007 APS Porter Physiology Fellowship and the Mayo Foundation.