Perifusate metabolomics interrogates nutrient exposure and oxidative stress response in kidney tubules

Understanding metabolism at the organ level is challenging, as tissue metabolite signals are transient and reflect transport, metabolism, and inter-organ communication. Here, we address this challenge by using a perifusion platform that enables time-resolved metabolite measurements in living kidney tissue under controlled input conditions. We apply this approach to native tubule and glomerulus preparations and generate >45,000 longitudinal, time-resolved metabolite measurements using targeted metabolomics. Tubules release tricarboxylic acid cycle and acetylated amino acid intermediates and show dynamic metabolic rewiring under oxidative stress. Amino acid exposure rapidly activates antioxidative and urea cycle reactions, improving resistance to oxidative damage in a sex-dependent manner. Supporting the translational relevance, metabolites released from tubules upon oxidative stress are also found in plasma from humans with acute kidney injury (secondary analyses of the original clinical trial NCT01534364). Thus, the approach developed here enables time-resolved interrogation of renal metabolic responses with defined metabolite inputs.