Medullary heating predicts hypoxia

This proposed mechanism asks whether blocking a kidney transport protein shifts work into the aging kidney's inner region, where oxygen may run short. Sodium-glucose cotransporter 2 (SGLT2) reabsorbs sodium and glucose early in the kidney tubule. Blocking it reduces that work. The hypothesis proposes that the medulla, the urine-concentrating inner zone, retains heat. Warming could raise cellular respiration and oxygen demand before tissue oxygen falls. A perfused kidney with local temperature and oxygen sensors could test it. If matching medullary temperature to a control kidney removes predicted oxygen overuse, hypoxia and reserve loss while transport and oxygen delivery remain matched, heat would be favored over rival explanations.