Increased hypoxia and reduced renal tubular response to furosemide detected by BOLD magnetic resonance imaging in swine renovascular hypertension.

摘要: Oxygen consumption beyond the proximal tubule is mainly determined by active solute reabsorption, especially in thick ascending limb of Loop Henle. Furosemide-induced suppression oxygen (FSOC) involves inhibition sodium transport this segment, which normally accompanied a marked decrease intrarenal deoxyhemoglobin detectable blood level-dependent (BOLD)-magnetic resonance imaging (MRI). This study tested hypothesis that magnitude BOLD-MRI signal change after furosemide related to impaired renal function renovascular hypertension. In 16 pigs with unilateral artery stenosis, hemodynamics, function, and tubular (FSOC fluid concentration capacity) were evaluated both kidneys using MR multidetector computerized tomography (MDCT) imaging. Animals adequate FSOC (23.6 ± 2.2%, P > 0.05 vs. baseline) exhibited mean arterial pressure (MAP) 113 7 mmHg, relatively preserved glomerular filtration rate (GFR) 60 4.5 ml/min, comparable their contralateral kidney (66 4 0.05). contrast, animals low (3.1 2.1%, = NS had MAP 124 9 mmHg GFR (22 6 ml/min) significantly lower than < The group showed an increase intratubular as assessed MDCT was greater observed group, suggesting better preservation former group. These results suggest changes can differentiate between underperfused those dysfunction. approach may allow more detailed physiologic evaluation poststenotic hypertension previously possible.