American journal of physiology. Regulatory, integrative and comparative physiology
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Am. J. Physiol. Regul. Integr. Comp. Physiol. · Aug 2019
Furosemide reverses medullary tissue hypoxia in ovine septic acute kidney injury.
In experimental sepsis, the rapid development of renal medullary hypoxia precedes the development of acute kidney injury (AKI) and may contribute to its pathogenesis. We investigated whether inhibiting active sodium transport and oxygen consumption in the medullary thick ascending limb with furosemide attenuates the medullary hypoxia in experimental septic AKI. Sheep were instrumented with flow probes on the pulmonary and renal arteries and fiber optic probes to measure renal cortical and medullary perfusion and oxygen tension (Po2). ⋯ Urinary F2-isoprostanes, an index of oxidative stress, were not significantly changed at 24 h of sepsis but tended to transiently decrease after furosemide treatment. In septic AKI, furosemide rapidly restored medullary Po2 to preseptic levels. This effect was not accompanied by changes in medullary perfusion or renal oxygen delivery but was accompanied by a transient increase in fractional sodium excretion, implying decreased oxygen consumption as a mechanism.